I must admit i have never ever thought anything negative about a family or married couple wanting to spend time together.
I understand if you are bitter or you dont actually enjoy your partners company then this might be difficult to understand. But even then i always imagine people have the intelect and sense to realise that its not one size fits all with families and just because they do things differently, they are not always insecure.
I love spending time with my DH, with our schedule we rarely get to do lots of the "mundane" things together.
He would love to be able to do the school run with me, i wouldn't miss out just because he wants to come as well.
He doesnt come to parties, although some children do have both parents turn up, but around here we are all quite chilled out and open, we understand that one out of the parents don't always get to see there child mixing and playing with all their friends, so it's a nice opportunity to do so as a couple. Its not any inconvenience in most cases as parents don't expect to be catered for and not many big parties happen at houses here, they hire out venues.
But OP really, just relax, live and let live, they are probably just enjoying their time together, enjoying their lives, while you are all judgy. I know which one i would prefer.