Accidentally on Purpose

Billie enters the kitchen to get herself some breakfast when Davis immediately notices an increase in her bust size. After Billie leaves, Davis questions Zack about his inability to get it on with her. Zack points out the golden rule and relationship boundaries he and Billie have set. Davis proposes to Zack to relieve his pent-up sexual frustrations by having "an all-by-yourself party" and being "a one-man band."

At the office, Billie talks to Olivia about the recent changes in her body when Brian, a news reporter and a friend of James, arrives and chats with her. James interrupts them and invites Brian out for a bite.

Later, Abby tries to borrow Billie's black strapless dress. Billie refuses to lend the dress to her sister since she is prone to spilling things ever since they were kids. Billie then goes on about how she is drawing attention from men and how it's been difficult for her to deal with her crazy pregnant hormones.

Back at Davis' apartment, Zack shows Davis the orange palm he got after mistakenly using sunless tanning lotion for his "ride on the alone train." Davis deduces that even Zack's junk has turned orange because of his recent mishap.

That night while watching a movie and snacking on popcorn, Zack and Billie both try their best not to break the golden rule and sleep together again. Billie calls Olivia to consult her regarding her dilemma. Olivia gives her the go signal. Billie comes on to Zack, who, after remembering the earlier incident with the sunless tanner, backs off and turns her down.

The next day, Zack goes to a beauty shop looking for a remedy for his orange crotch. The makeup saleslady suggests that he use coconut milk to reduce the coloration on the affected area.

Meanwhile, Billie shares her frustrations with Olivia and Abby, who continues to pester Billie about the dress. Olivia believes the solution to Billie's problem is to find another man to sleep with while Billie thinks she should just remain celibate for the next five years.

At Davis' place, Zack succeeds in turning his skin back to its original color with the use of coconut milk while Davis has his excuse to just stay at home and drink beer.

Back at the office, Brian invites Billie out for dinner after she reveals her pregnancy and the setup she has with a much younger guy. Hesitant to go out with a married man, Billie then learns that Brian is now divorced and agrees to meet with him later.

After dinner, Brian asks Billie up to his room. Billie then phones her sister and fills her in about her situation. Abby, who is at Billie's apartment raiding her closet, places her confidence in Billie that she is wise and strong enough to do the right thing. Zack catches Abby "borrowing" Billie's things and learns that Billie is about to get laid with another man.

Zack hurries to the hotel and confesses to Billie his real reason for not sleeping with her earlier. Billie, on the other hand, apologizes for her behavior. They finally agree on just remaining friends and maintaining their no-sex policy for the meantime.