Here's one that has only come up in the past year or so... I'm sure a lot of people have dealt with this before, but I'm in my thirties and have only ever dated three people my whole life. The first one, all his friends and I got along great and we all played in a D&D group together. The second one, that I later married and then divorced, I got along with all his friends in college, and he never really socialized much after that outside of video game tournaments that I was never involved in. Now FH has two friends that I really have trouble tolerating.
One of them absolutely infuriated me by going on and on about how a mutual friend of his and FH was pregnant, how she was so stupid, and how she needed to have an abortion and get herself sterilized. I have previously been in a similar bad situation, with people similarly giving me orders about what to do in some cases supposedly in my best interest and in some case in theirs, and I found this incredibly offensive... to me, that should be her decision and not the decision of some gossipy friend of hers, and finally couldn't take anymore and quietly excused myself, with the excuse that I had to do something with my instruments for a performance I was doing later - and sat there for an hour by myself pretending my harp was badly out of tune. Later after we were alone I gave FH my thoughts on the matter, and he said he agreed and told his friend much the same thing. He still wants to invite this guy to our wedding, which I guess I can tolerate since it is only a few hours and there will be a lot of other people there to converse with, but I have made it clear I'm not interested in going along to socialize at this friend's house.
The other is his "best friend". He has repeatedly missed dinners that we have scheduled together, that I have cooked and picked up nice desserts for, made the hour drive out to FH's home town for, and my daughter has gotten all excited about hoping to play with his kids. He continually complains about having to pay child support to his ex-wife (as a divorced mom I receive child support myself), and at times makes comments about his personal life, either forgetting I'm there or not caring I'm not sure, that are way more personal than I want to hear. He is supposed to be the best man at our wedding but I'm not sure how he is even going to get out here for it since he hasn't registered his car or paid insurance on it for a year and expects to mooch rides off of everyone (we are all in our thirties, not high school or college where that might be understandable). The last thing I want is for him to stay the night in our family room on our wedding night then get a ride back in the morning (something FH actually suggested til I put my foot down and said no way on earth anyone stays the night at our place on our wedding night!) And his daughters are my flower girl and junior bridesmaid because annoying friend and FH asked me in front of the girls if they could be in the wedding party so I couldn't say no and upset them - a minor thing and I can deal, but added up it all gets annoying.
How does everybody else deal with, or get out of dealing with, their SO's annoying friends?