How to avoid friend's gropey husband?

My friend and I are both over 40 and have been friends 15 yrs. 6 yrs ago she married this creep who I only met once, but he was touching me and taking photos of me the whole time I was around (she saw this and pretended not to). Thankfully I've avoided him since but now they're having a party and I need an excuse not to go. I just feel bad because I'm always making excuses.

She does "love" him though she knows he cheats. She wants a baby. He's most likely there for the green card as she is very different looking from his ex wives, whereas I am not. I am still friends w her because this marriage will end eventually.