Kids Birthday Party

My nephews 2nd Bday and we are 5 weeks postpartum. When we got there (my in-laws house) we just got a hello, handed the bday boy his gift and neither my SIL or her husband ever bothered to make rounds as a host. Especially since they hadn’t seen our newborn twins yet. At least to sit down for 5 minutes. They only were grouped with their friends and family was left on the side. I’m so disgusted by their behavior, I don’t want to go to any future parties they host. It feels like we’re only there because we’re family and have to attend.

Am I overreacting here and am I asking too much to be courteous on their part as the hosts?