Hillary is behaving really nicely towards Dave and it's freaking him out because it is so unlike her. Finally, seeing Vicky chilling out after a session of lovemaking, he realizes why Hillary has been so relaxed: She must be having sex!
He becomes convinced she's having sex with someone. And asks Mike to let him know what he has heard. Mike (who always spies on her anyway) tells Dave that he is wrong and that Hillary is still a virgin. He is hapy to hear it, but he is still concerned about why Hillary is being so nice to him.
Dave goes upstairs and decides he wants to smoke a joint, but he discovers that his stash is missing. Dave and Vicky argue over the fact that they were both supposed to have stopped smoking in order to try and become responsible parents, but Vicky is more upset by the idea that he has been smoking without her. Dave confides in her that she is annoying and talkative when she's high.
Meanwhile, Larry has auditioned for and gotten a part in the school production of the musical "Annie Get Your Gun". Needless to say, Larry wanting to be in a musical is not a comfort to Dave.
Dave and Vicky come to the conclusion that Hillary must be smoking his pot, but she denies all knowledge of it. As he's confronting her about it, though, he accidentally tells her that its his stash that has gone missing. Vicky, not too impressed with his parenting skills thus far, throws her hands up and offers him no help in getting out of it. Thinking quickly, he lies and tells Hillary that it's not really his - it belongs to Grandma Betty, who uses it for medicinal purposes. Hillary maintains her innocence and storms off. Mike overhears part of the conversation and feels badly that his grandmother's weed is missing, so he goes off to the schoolyard to score some dope for grandma.
In the end we discover that Hillary had indeed stolen the dope because she likes to smoke. She can't find it, however, because her brother Larry had stolen it from her in turn. Larry doesn't use drugs and has no interest, but he is convinced that he can use the dope to lure a girlfriend from among the cast members of the school play. Vicky finds it in Larry's drawer and she confiscates it.
Vicky comes home high from her book club meeting, and Dave can tell by her behavior that she found the missing stash. Dave confronts her and they decide to really flush the stuff this time, stating that getting high at their age is just pathetic. Meanwhile, Grandma Betty and a friend are at getting high with the stuff Mike gave her.