There are a group of us who go away on short trips several times a year. A mix of couples and singles, sometimes partners come, sometimes they don't. The group is fluid, so whilst there's a core of people, not everyone goes everytime iyswim.
We have one planned in a few weeks and one of the men has had to drop out because of a family situation. This leaves a spare bed in his wife's room.
We've asked some of the usual women but none of them can make it. There is a single man who has been with us previously, who would like to come. The husband of the woman he'd be sharing with is OK with it, she's fine with it. We've all been friends and shared in various combinations for a long time.
However the replacement man now has a fairly recently new GF. He's smitten, says it's all going very well etc. There's not room for her to come too and as I said , he'll be sharing with a long standing (married) female friend.
Would you expect him to come? Would you be ok with that if you were the new GF.