I've been invited to the 50th birthday party of a guy I used to go out with 25 years ago. It's a big do in the town in which I went to school. There will be loads of old friends going of whom I haven't seen in years. I will have to stay at my sister's for the night and return to London the following day (it's 300 miles away). DH thought it odd that I would be invited and seems to have an issue with it. He asked me if I would be ok with him going to an ex girlfriend's party in another city - and I said yes I would be fine with it which I think he finds odd too.