The in-laws

My MIL told me last week I should drop by for coffee this week with my mother. Last weekend my FIL's birthday party and they had invited their daughters in-laws but never bothered to invite my parents. So it felt a bit unfair and wasn't up to having a "girls" get together. I used my prenatal appointment to get out of it. My MIL has a tendency to get bored fast and her attention span wonders around, which usually signals time to go. I'd love for the inlaws to get along but somehow it feels strained.

My question is how important is it for 2 families to see each other and get along?

××× Thanks for your input! I thought it was weird that in-laws don't see each other often. This post has opened my eyes that it would be nice but not necessary ×××