I refer to her as a distant friend; although we used to be close and I was bridesmaid at her wedding 10 years ago. That being said, I have only seen her once in the last 18 months at a friends birthday party.
The last time my FH saw her husband, my FH was asking him to leave their family home at the request of my friend; due to the discovery that a "one night stand" her husband had with a colleague of theirs, actually turned out to be a longer affair.
After sending out the invitations my friend messaged me to ask whether her husband was invited to our wedding and, because I'm a coward; and we have already pissed off family (mainly our parents) by having an adult only wedding due to being on a budget, I told my friend that her husband was on the reserves list so I'd be able to confirm after the RSVP date. I did wonder whether she asked because she wanted to know if they needed to sort childcare but she never replied to my message and hasn't RSVP'd yet. She has also complained to friends that her husband is on the reserves list, so I don't think it's childcare related that she asked. I can't quite fathom why her husband would want to watch us get married. It is quite clear that I do not like him, nor does he like me.
Incidentally, We have also invited colleagues without a plus one, despite socializing more with them, again due to being on a budget and they seem to have understood and accepted the invitation without issue.
So was I compete twat (and unreasonable) for not inviting her husband to our wedding?