my hubby has this friend (he always brings his gf), and I hang out with them because I'm forced to…

my hubby has this friend (he always brings his gf), and I hang out with them because I'm forced to be nice. everytime I see the gf she constantly whines about how my life is so much better than hers, because I have my own apartment, I'm engaged and I'm pregnant. I have definitely felt jealous of people before but that's literally all she wants to talk about. when she was drinking the other night she told me she was going to "forget" to take her pill so she could get pregnant. she constantly hounds her boyfriend for a baby and threatens to break up with him if he won't get her pregnant. I feel oddly.. responsible that he's so miserable? but she's gone psycho..