I am not sure why you haven't brought this to her attention. If you feel very strongly about the sister finding 'play dates' for your husband then go talk to her. The comment made me concerned. You said your husband/partner has AS but it is undiagnosed. You should take him to get him checked out, it would make both your lives a lot easier. On top of that, you need to learn that sometimes people want a break from 'couple' things. You originally said 30yr olds and then 20 year olds at the end, I am not sure the age of these new neighbors, but guys tend to bond over odd things no matter the age. You need to take some time for yourself. If you husband is happy going out once or twice to hang out with his sister then you should chill out. He isn't cheating on you, and your yelling is not helping. She was his sister before you were his wife and there are some things you will never fully understand. You are being a bit unreasonable. You want to do couple things, find a nice couple yourself.