NOTE: This spoiler was sent in by Amy.
The movie begins by showing Tank (Dane Cook) dropping off a date at her house. The night has clearly gone very badly and the girl can’t seem to get away from him fast enough. Tank starts talking about how he thinks she should give him oral sex and while with other guys that might seem like a chore, he likes to think of it as a tutoring session and a way to teach women to improve their technique. The girl is clearly very offended and slams the door in Tank’s face. He’s not done yet, though. He knocks and asks her to give him one reason why not, and she angrily agrees to give him not one, but ten reasons.
We then see a montage of every jerky thing Tank did to her that evening, including picking her up while playing a very loud, offensive song on his stereo even though she had a headache. He also took her to a trashy restaurant with questionable health practices (she threw up as a result), critiqued her weight, and was basically an a**hole to her for the entire night.
This causes the girl to call her ex back, a guy named Josh who is seen paying Tank. Apparently, Tank has a little hobby. If a guy loses a girl and wants her back, he gets in touch with Tank and pays him to take this girl on a date. Throughout the evening, Tank inevitably behaves in the most moronic fashion, thereby making the girl realize that her ex wasn’t really such a bad guy after all. It’s always worked and Tank is very good at being a jerk to girls.
After getting Josh’s girl to go back to him, Tank decides to pick up a girl for himself. He goes up to one attractive girl and says that she’s so tall and white; he should just lay her down on the bar and snort her. This offends the girl she is with, who says he shouldn’t talk like that. Tank calls the other girl jealous because she is chubby. Rather defensively, the girl remarks, “I just had a baby!”
“And I’m sure it was delicious,” deadpans Tank, which causes the girl to stomp off.
The other girl who Tank was originally hitting on seems to think Tank is a jerk as well, but that doesn’t stop her from going home with him. Right before they leave, Tank sees Josh leaving with another girl. This upsets Tank because he went to a lot of work to get Josh’s girl to go back to him and apparently he doesn’t even care about her. You can tell that Tank is kind of a romantic.
Despite this romanticism, Tank and the random bar girl spend the night together, but are woken up the next morning by Tank’s best friend Dustin (Jason Biggs). Dustin is bringing over a giant crate full of porn for Tank. He says he won’t need it anymore because he’s fallen in love with the most amazing girl.
Dustin is obviously the polar opposite of Tank. He’s kind, sweet, genuine, and tenderhearted. He’s fallen for “an angel” named Alexis (Kate Hudson) who works with him. Dustin takes Alexis out for a steak dinner, which Alexis rather guiltily eats because she knows Dustin is a vegan (he also ordered steak). Dustin doesn’t touch his steak, but he wants for Alexis to like him so badly that he ordered one. During the dinner, he comes on really strong, telling Alexis first that he loves watching her eat and then that he loves her even though it’s only been five weeks since they first met.
This somewhat freaks out Alexis, who thinks they should be taking things slowly. Dustin can’t seem to stop from putting his foot in his mouth, though, and he suggests they move in together. After listening to Dustin ramble on for a little bit, Alexis finally excuses herself.
Later that evening, Dustin admits what happened to Tank. He knows that he’s lost Alexis and wants Tank to get her back. Tank doesn’t want to because apparently Dustin is his step-cousin or something, so even though they aren’t blood related, Tank considers him family. After a while, Dustin realizes he couldn’t allow Tank to emotionally manipulate Alexis like that, and agrees that Tank should not take Alexis out. Unfortunately, the next day Dustin sees Alexis flirting with another co-worker, which drives him crazy and ultimately, he begs Tank to take Alexis out.
Alexis is training for a marathon, so Tank arranges to meet her in a cutesy way at the park where she runs. He starts running beside her and then deliberately trips and falls to get her attention. He ends up banging his knee up, but he gets her number and a date with her.
The night of Tank and Alexis’s date arrives. Alexis is talking with her roommate Ami (Lizzy Caplan) about the upcoming date. Ami thinks Alexis, who’s only slept with two guys, should start sleeping with more men before settling down with a nice guy. Somehow, before the date even starts, Alexis ends up a little drunk. However, this just seems to relax her.
When Tank pulls up in his car, he begins being a complete jerk, just as he did to the girl before her. He plays “Pop That P*sssy” on his car stereo very loudly, but Alexis actually starts singing along to it because she almost lost her virginity to that song. Tank is surprised, and it won’t be the first time she takes him off guard. Tank takes her to a strip club, but Alexis doesn’t really seem to mind. She just kind of goes with the flow. It isn’t until Tank says point blank that he thinks they should sleep together that she appears mildly offended. When Tanks takes her home though, Alexis considers Ami’s advice and invites him up to her room. This takes Tank aback, particularly when she kisses him very passionately. Of course, he can’t sleep with her because she’s Dustin’s girl, so he backs away and drives off.
When he gets back to the place he shares with Dustin, the latter is excited because Alexis called him and wants to go out for lunch. Dustin thinks he’s gotten her back. Unfortunately, it turns out that Alexis’s date with Tank made her realize that she hasn’t really dated that much and she thinks that they should just be friends. This is devastating to Dustin, who wants Tank to see her again and be an even bigger jerk. Tank doesn’t think Alexis would even want to see him, but apparently Dustin sent Alexis dozens of roses in Tank’s name and wrote an apology poem.
Tank is determined to alienate Alexis this time. He marches up to her door and says that he can’t sleep with her because she’s unattractive and a “two-bagger,” meaning that he would need a bag over his own head in order to have sex with her just in case the bag on her head fell off or something. Alexis asks snidely if it’s “just a size thing” in reference to Tank’s penis. Then Tank says that it’s because Alexis’s butt is too big. Alexis takes his hand and places it on her butt and asks, “Do you really think this is too big?”
In turn, Tank puts her hand on his crotch and asks, “Do you really think this is too small?”
Then they end up making out and sleeping together. It’s clear that both of them enjoy it quite a bit and that is just the beginning of their weird relationship. Dustin is still in the dark about Tank and Alexis and he keeps doing cute little things to try to win her back, but it isn’t working. Tank and Alexis are getting closer and closer. At night, Tank even snuggles with her and wraps his arms around her while they sleep.
Tank is becoming confused by the depth of his feelings for Alexis and also feels bad for betraying Dustin. He goes to see his father, Professor Turner, who is a women’s studies professor at a university. Despite being in women’s studies, he is extremely misogynistic and it’s evident that Tank probably learned a lot of his behavior from him. Tank goes to his dad for advice, but his dad doesn’t tell him much, only that he’s nothing more than a booty call to Alexis.
Tank decides he wants to be more than that, so he asks Alexis out on an official date. They go to a high school prom because Alexis never went to hers. The chaperone of the prom is a very religious girl who Tank once “dated” but he ended up admitting the scam to her because he felt bad for making her cry. She was so impressed with his honesty that when he admitted he really liked Alexis, she gave him advice and let him and Alexis come to the school prom.
After their date, Alexis and Tank go back to her place and Tank is giving her a piggyback ride around the house when Dustin comes over. He’s drenched from the rain outside and is desperate to see Alexis because he misses her so much, but he’s shocked when he sees Tank there. Alexis doesn’t know that the two of them know each other, so things are pretty awkward. Tank feels just awful and both he and Dustin leave and Dustin kicks him out of the apartment.
Tank talks to his dad again, who offers him some better advice this time. His dad admits that with Tank’s mom, he knew that she was the absolute best he was ever going to get. He just never asked himself if he was the absolute best for her. As a result, they didn’t work out.
A little while later, Tank and Alexis are going to her sister’s wedding. When they arrive, her sister is shocked because she went on one date with Tank and it was a disaster. Her fiancé is Josh, the guy from earlier in the movie who cheated on her with another girl. Josh instructs Tank not to say one word about their arrangement. Apparently, he really wants to marry Alexis’s sister because their family has a lot of money.
Tank is disgusted. When he goes inside, he overhears a conversation between Alexis and her sister. Her sister doesn’t believe that Tank could be as nice as Alexis thinks. Alexis just wants for her to give him another chance because she thinks that she loves him. Tank is shocked and goes into the bathroom. In there, he looks at himself in the mirror and asks himself if he is the absolute best for Alexis. He thinks the answer is no, so he sets out to alienate Alexis.
First, he starts smoking in the church. Then, he sneezes all over the food at the reception. He tells inappropriate and sexual jokes to a group of young boys and to a rabbi and a priest. He interrupts the first dance between the bride and groom and throws up all over them because he drank so much. He tops it off by hitting on Alexis’s mom and then propositioning her for a blowjob.
However, the icing on the cake is when a drunken Dustin appears and exposes Tank. He tells everyone at the reception that Tank goes out with girls for money and is a real jerk to them so they go back to their exes. Alexis begs for Tank to tell her that it’s not true; she wants him to look her in the eyes and tell her she’s not just a job. Tanks looks in the eyes, and says that she’s just a job. Josh, who was exposed, then punches Tank and the latter is roughly escorted out of the reception.
A little while later, a sober Tank is hanging out with his dad and Dustin. Dustin has realized that Tank must really care about Alexis *and* him if he would give her up. Tank’s dad says that Tank must have taken after his mother, after all. With their encouragement, Tank decides to try to win back Alexis.
It proves to be a daunting task. Alexis and her whole family hate Tank. The film flashes forward to three months later. Tank is on a date with another woman, although he is not enjoying himself. Alexis is at the same restaurant sees them, so she goes up to them and makes up a story about how Tank got both her and her sister pregnant. Tank recognizes that it is a story her told her on their first fake date in one of his attempts to piss her off.
The two begin slamming each other with one-liners. In front of everyone at the restaurant, Alexis says that she just saved Tank’s date from the worst sex of her life, to which Tank replies that her mother didn’t have any complaints. He adds that he would kick her a**, but he wouldn’t want his foot to get sucked in. Alexis says that she would kick him in the crotch, but she wouldn’t want her foot to get herpes. After trading passionate one-liners in front of shocked patrons at the restaurant, they begin passionately making out.
As the credits roll, we see Dustin and Alexis’s roommate on a bed together making out.