In sum, the visit went well.
I had to fight with all my might not to pry into the situation concerning the dog and I even bit my tongue when her son was showing me videos of the new "doggy" he wanted to get. Their old dog is currently in a box in their (shared - it's a co-op town home) backyard. (Ew.) I can't control what they do. I can't even voice my opinion because they don't see anything they're doing (concerning animals) as wrong. Her son was showing my these videos while
she was talking about how she's planning to get rid of her cats. My plan is to call the SPCA anonymously if they do get another pet. That's all I think I can do. Communication will cause problems and if I have to do what I think is right passive aggressively (I'll deny it if they ask me if I called), then so be it. This issue is done and over with.
My new plan is to go visit them, but only on special occasions. Birthdays. Christmas. That's it. If my husband wants to go, he's welcome to it. A little space between him and I is probably a good idea, too. (To the poster who asked about how much time we spend together the answer is a lot: We have the same hobbies and we play on the same team so 3 evenings/week we are either playing together or supporting each other. In comparison to "other" couples in my social circle we spend a lot of time together.) When we have plans we don't see them, but I feel on the weekends we don't (which is about every other weekend as we're relatively social, but definitely don't go out every weekend) he wants to go to them. I wish he'd want to limit this to 1x/month, but the choice is his. I have more than enough hobbies to keep me busy.
What broke my heart was seeing how happy he was while there. He wanted to hold the new baby. Skype his family in Europe and play with the older children. He was smiling a lot and I don't want to take that away from him. He was supportive of when I wanted to leave, as well. (We agreed on a 2 h visit.) His sister made a comment about why I'm leaving and I just said "I have stuff to do." She said, "You always have stuff to do." I left it at that. The biggest difference between his family and mine is that I can't sit and chit chat all night. I get antsy and need to move around. They are very much couch sitters which is cool, but I wish they'd understand why I can't do it.
Thanks everyone for your responses. I hope I can get through this, but it's going to take a lot of energy and effort and more posts