Katie walks into the living room where she tells Hope that her ex-boyfriend Ben invited her to a trash 'n treasures party, a party where you bring an ex boyfriend or girlfriend and hope to meet someone. Katie is sickened by it, and Hope also seems to be, but then says that they should go. Hope suggests bringing David, but says that brining her boss would be weird, and so would trying to date Mark. Hope tells her to at least come for her sake. Mark and James walk in and Hope tells them about the party and tells them to line up their exes, "if they even bothered to learn their names". James says he is all for it and then jokes that Mark doesn't have anyone to bring. He responds that he has plenty of them, and Katie asks who he will bring. He responds by saying a lot of girls. Hope and Katie then start to talk about who Hope should bring and Hope is thinking about Russell, but Katie reminds her that she dumped him because he is gay.
Mark goes to Thom's apartment where Thom is trying to talk to a bird. Mark tells him that it isn't a parrot, but Thom denies that. Mark tells him about the party and says that he doesn't know what is going to happen with Katie. Thom tells him he has to bring his only ex, Jackie, otherwise he will be mocked. Mark says that he can't take her, but Thom reminds him that she is the only girlfriend he has had, and he was a terrible boyfriend at that.
One of Thom's neighbors named Alyssa walks in and sees Mark is there. She asks why mark hasn't called her and he makes up that he doesn't have her number. She then gives him a business card. Thom then says that he wishes he could go to the trash 'n treasures party. Alyssa says that she loves parties and she wants to go. Mark says that you can only go if you are an ex. She then kisses Thom, pretends to find another woman's hair on him, slaps him, and says that now they are exes. She then leaves. Thom just smiles over this.
At the parry, Hope and Katie are at the bar when Ben comes over to Katie. She says that she looks great, and she says the same thing to him. She goes to say something else, but then another girl comes and grabs him away. Meanwhile, Thom, Mark, and James are at a table and Thom says he can't wait for Jackie to show up. He then asks James who he invited, to which he replies, the drunkest, loosest, hottest girl he ever dated. Thom then asks if she has a grandma, saying he loves old drunk ladies.
A girl walks into the bar and Katie asks if it is Mark's ex, but James says that it is his and he goes to talk to her. Katie says that he is already talking to someone else, and Hope says that it is just gay Russell. Katie says that of course he's gay, he's really cute.
Alyssa then walks in and sits on Thom's lap. She says that she and Thom got back to together and asks Mark if he is jealous, and he says no. She says he will be and she takes Thom to the bar. Mark and Katie then start talking, and then Mark's ex Jackie walks in. They say hi and Mark says that she looks so good that he didn't even recognize her. He then introduces her to Katie. She finds it weird that Mark is now living with Katie and Katie seems flattered that Mark talked about her, but he brushes it off saying that he talks about all of them. Katie says that she is going to go find some "treasure", while Jackie wants to catch up with Mark. Katie seems jealous of this and says that she is going to follow the rules and look for someone new, and you can't do that sitting on your butt.
Meanwhile, James is talking to his ex and finds out that she no longer drinks, which surprises him. He asks what she does for fun now, and she says hopefully him, which excites him. Katie and Hope are with Hope's ex "Gay" Russell and Russell is holding Katie's bag saying that he loves it. Hope tells him to stop talking about bag and to go distract a girl so she can talk to a guy. Katie starts to talk to Hope and how Jackie and Mark are acting and is somewhat annoyed that she is not looking for someone new, yet she claims to not be jealous.
James is still talking to his ex, when her phone rings. She says that needs to go outside and take the call, but tells James to stay put. Mark and Jackie are talking about how she is now an astronomer, and Mark jokes about the sun exploding and raining fireballs. James' ex comes back in with her son, and James is shocked by this. His ex says that she needs to go home because of her son, but James tells them to stay and have something to eat. She leaves to go get something, and then Graham (her son) tells her that his friend Max tooted in his face. James then says that he tooted in his roommate Mark's face last night, and the two begin to laugh at Mark.
Mark and Jackie come back to the table with beer and Jackie says that she was actually thinking about Mark before he called. She wanted to know how he was, and then Mark offers to show him his apartment. They go to leave, and Alyssa continues to try and make him jealous. It doesn't work, and so Thom says that he really needs to use her, so they stat kissing.
Hope goes to James' table and James introduces her to his ex, Anna, and her son. Hope says hi to Graham and says that he is cute. Graham responds that he has lots of girlfriends. This makes Hope laugh and she jokingly asks James if he is sure that Graham isn't his kid. He just smiles, and Hope leaves telling Anna to watch out for James, and she says that she will.
James asks Anna hold old Graham is, and she says he is six. James then covers Graham's ears and whispers "Am I Graham's daddy?" Anna says no and James is relieved. Graham says that he needs to go to the bathroom really bad and Anna gets up to take him. However, Graham wants to go to the boy's bathroom with James. James says he doesn't mind and will take him anywhere since he's not his kid.
Back at the apartment Mark and Jackie are looking at pictures and Mark comments on how hot Jackie has become. They begin to reminisce about their days as a drill team member and mascot and joke about it. Jackie then tells Mark to go get the horse head from his mascot outfit.
Katie goes to see her boss David Schick, but the doorman makes it seem like it is a bad idea. Katie asks him why he thinks that way and Katie starts to open up about her situation, and it ends up leading nowhere.
Back at the bar, James is in the bathroom waiting for Graham, and Graham starts singing. James tells him to stop and just get on with it. Graham then asks James to help him wipe. James says no, but Graham asks again and he goes into the stall. He is then horrified after seeing what Graham has done.
Outside, Hope is going to the bathroom and notices Russell is kissing a girl. She asks what he is doing and he just replies, kissing. Hope tells the girl that she is kissing a gay guy, and they girl responds that she has done that, and he isn't gay. Hope wants to know what is going on, and he says that he tried to break up with her in college many times because she was nuts, but ultimately he and his friends decide that he should pretend he was gay. Hope is angry, but says that from now on they will tell people she dumped him, and then he leaves.
Back at the apartment, Mark brings out the horse head, and Jackie asks him if he still remembers their cheer. He says no. Jackie says that she thinks of Mark as "the one who got away". Mark then says that it has been nice to see her, and then they kiss. Jackie then says goodbye and she leaves.
Later that night, James is in the kitchen when Hope walks into the apartment. He asks her how things with Gay Russell went and she bitterly replies that he isn't gay. He then talks about how frat guys often think of ways to dump girls. Hope shuts him up by asking how things went with Anna, and he replies that the mood was ruined after he had to help clean up Graham's "Jackson Pollock" in the bathroom stall.
Hope then says that she will never go to a party like that again, saying things are weird with exes. James agrees and says that is why he will never make a move on her or Katie. He says that they would never get over him once he didn't want to date them anymore. She responds by saying that it would be him who couldn't get over him once they dumped him. They begin to fight over who is right, and then all of a sudden Hope kisses James.
They break apart and say that what they did was wrong since they are roommates. However, they eventually end up in bed and have sex. After the first time they again say it was wrong, but end up having sex a second time.
Later that night Thom and Alyssa return to Thom's apartment and Alyssa says that she had a good night. He says that she doesn't need to pretend, but she says she means it. He then asks her to take a bath, and she slaps him. He then says a shower and she slaps him again and leaves. Then, as the episode ends, all of a sudden Thom's bird Jo-Jo speaks the words he was teaching her earlier.