Chelsea invites her beautiful college roommate, Gail to stay at the house while she gets over a bad breakup with her boyfriend, Brian. Charlie is struggling to resist his temptations toward Gail and wonders if Chelsea, who has a problem with him not listening, is testing him. Meanwhile, Berta suggests he use Alan's romantic ineptitude to solve the problem which proves successful.
Charlie doesn't really listen to people talking. Chelsea finds that out the hard way when she reminds Charlie about dinner plans they have with her college roommate. Charlie seems not to know anything about it, which causes Chelsea to berate him for not listening. He's too busy having a conversation inside his head about whether or not he should pee before they go.
At dinner, Charlie's selective hearing only gets worse. It turns out the roommate, Gail, is awfully attractive and has just been dumped by her boyfriend, Brian ("Life of Brian, funny. Brian's Song, not so much"). Chelsea offers to let Gail stay with them for a while, and of course, Charlie agrees. Mind you, he has no idea what he is agreeing to because during the conversation, he's wondering whether or not the two women ever experimented with each other.
Back home, Charlie goes to Alan's bedroom to give him the good (matter of opinion) news about their new houseguest. What he doesn't expect is to hear some shaving going on, and then Alan walking out of the bathroom, pulling up his pants. I'll spare you the details, but know that Charlie will probably be hiding his razors from now on. Anyway, Alan doesn't seem too keen about giving up his bedroom. That is, until he meets Gail. As she is going on and on about how nice it is for Alan to let her stay in his room, his brain can only process a few words: "Gorp. Fnark. Shmegle." He also, in his head, proposes to her and offers to bear her children. As the brothers watch her walk back to her new room, Alan mentally hums the wedding march, while Charlie opts for "brown chicken, brown cow."
That night, Charlie finds himself down in Gail's bedroom, watching Chelsea comfort her. Both woman are dressed only in nighties, and seem all too anxious to have Charlie join them. When they invite him to stay, his brain can only process a few words: "Gorp. Fnark. Smegle." Charlie may be a lucky man, but he's not that lucky. As he suspects, it's only a dream, but he makes the most of it and gets a little freaky with Gail. At least he still has a little fun, even if it's only in his subconscious.
By the morning, everyone has met Gail and everyone seems a little smitten with her. Jake graciously brings the bikini-clad guest some fresh towels and has a conversation with her about her niece. Actually, Gail has the conversation with herself, as Jake can only focus on one thought: "boobies." Even Berta raises questions about her sexual preference when she can't stop staring at her. I love that Berta isn't afraid to speak her mind about anything! Alan, of course, is pretty sure that there was a spark between him and Gail when they met, though Charlie assures him that she was only warming up her taser. Poor Alan.
It becomes poor Charlie a little later when Chelsea goes to work and leaves him alone with Gail. He's pretty sure that it's a trap to test his fidelity. When he hears Gail crying he offers her comfort, and she (jokingly?) asks him if Chelsea would mind if she borrows him. Test or not, joke or not, Charlie hightails it out of there. Berta is waiting for him in the kitchen with some liquor and advice on how to get rid of the temptation. She tells him that he needs the one tool guaranteed to drive women out of his house. On cue, the biggest tool of all walks in — the Alan wrench.
In an attempt to get Gail out of the house, Charlie convinces Alan to try his hand with her, who just might go for him in her vulnerable state. It becomes poor Alan again when he actually goes for it. It turns out women have conversations in their head, too. As Alan tries to be oh-so sensitive and seductive, Gail's personal conversation goes something like this: "Oh God, no." A swarm of angry bees couldn't have made Gail move as fast as she did to pack up and head out. Alan, not sure where they were leaving things, asks if he should call her or will she call him? She'll call him. When Charlie asks how things went, a confident Alan replies "You heard her, she's gonna call me."