They all overreacted, but I think the only thing Jen did wrong though was call Luke a bitch. Honestly, get over it. The laughing by those two is a common reaction when the opposition in an argument is being silly. I do it all the time. If I'm arguing with someone and I think what they say is stupid, I laugh at them. Jen and Kisha basically moved on in last night's episode. Margie and Luke are being immature pansies and are still letting it bother them.
I'm rather disappointed how not enough people are shaming Margie about the whole "you're black and have faced oppression" line. I know a few people have touched upon it, but COME ON!!! That's insane!
If anyone watches Seinfeld, there's one episode in which Jerry makes a joke about his Uncle Leo, and Uncle Leo's girlfriend laughs, making Uncle Leo break up with her because he think's she's an anti-Semite. No analogies are perfect, but this is basically the same thing.