Without your DH?
I do, and have many times. Partly because DS and I fly home a lot while DH works, but even if that were not the case I still would. I just wonder if others would too. Before DH and I were married I went to his cousins baby shower (obviously without him) My mom was surprised I went and said she would never do something like that with my dads family when she was my age. They are all really close now, but not when she first married him. But I get along great with his family and extended family.
Re: s/o Would you hang out with your IL's
Nope. ?MIL is crazypants so I need witnesses and backup when I hang out with her. ?
I do all the time. My MIL lives in St. Louis, we live in Detroit. When she is in town, she usually stays at SIL's house. I drive DD over there almost daily and we hang out alone or go to lunch or whatever. I also take DD to stay at her house without DH frequently. I will make sure DD is close to BOTH sides of her family and will make any effort necessary to see my IL's, even when DH isn't available.
I also go to all of my nephews' events. (DH's sister's kids). Katy and I drive an hour to go to their soccer games, school plays, family night at school (not parent conferences--it's more like a family fun night fund raiser for their catholic school). DH is rarely able to go due to work but I make sure I represent the both of us at all the family events.
Since I work full time I don't tend to spend a lot of time hanging out with the kids and my MIL. She's nice enough and all, but I just have so much to do on weekends I don't have time to run up to her house and spend a lot of time there. Once in a while I will. I spend time with my SIL however, but she also has kids and my kids and her kids like to play together so we get together often enough. I will go to baby or bridal showers etc for my ILs even w/o DH, and I did even before we were married....but now I must admit with a full time job and 2 kids I'm a little selfish with my time w/ the kids on the weekends....I don't like to share.
Before my MIL passed away I would hang out with her and my SIL w/o MH when we went to visit. I would not/will not just hang out with my FIL without MH there.