My X-MIL (sort of, as in we weren't married) has contacted me by text to ask if I am free to go round to theirs for a barbecue at the end of the month. I really don't want to go at all. I don't speak to XP other than at handovers with DS and I just have no desire to be in contact with any member of the family, TBH. I also have visions of her grilling me about why I left XP or going on and on about what a good dad he is to DS (which is great obviously, but I don't really want to hear it)
I think that XMIL might take offence however I word my reply, but I want it to be polite at least.
The other thing which is complicating things slightly is that when I first left XP I didn't want them to miss out on seeing DS so I offered to take him round there and have met up with XP's sister a couple of times (she is 14) to take DS swimming etc. But I now know that XP takes DS over there regularly, so I don't really need to keep this up, I haven't said anything yet though.