You might want to watch it for yourself to see if our impressions are similar. Most of the relevant stuff is in Part 3.
Anyway, the first episode of Meet the Browns I saw was "Meet the Ex" in which Will's old friend, a woman named Lynn, makes a pass at his wife, Sasha. Much homophobia/biphobia ensued--Sasha was suddenly scared of Lynn and didn't want to be near her. Lynn describes her feelings as, "I love men... women... everybody!" In other words, she's a slut. She's so low she'll come on to her best friend's wife.
Her bisexuality is explained as experimentation--no real attachment or attraction she just wants to "experience as much as I can," "live life to the fullest," "take a walk on the wild side," etc. Sasha is so repulsed and threatened, she is no longer even willing to go out to dinner with Lynn, and doesn't want Will to go, either. When Will speaks highly of Lynn the next night, Sasha must quickly point out that Lynn is not worthy of praise because she is bisexual--the exact words, "Lynn's not who you think she is." All of Lynn's work as a well-traveled, smart philanthropist was negated by her bisexuality.
Even after they confront Lynn, she still urges them to stop being uptight and "spice things up." She's also revealed to be immature--she says she just wants to have some fun like they did in college, at which point Will reminds her, "We're not in college." "Not everyone," Sasha tells her, "shares your lifestyle." Lynn admits that she doesn't like rules and the couple bid her a very definite goodbye.
So, Lynn as bisexual is promiscuous, mostly experimenting, a potential homewrecker, a rule breaker, trying to lure people into her lifestyle.
Yep, I think he covered all the bases. And this gets national coverage.