I've run into my first one...a little backstory:
I met this girl a few years ago through our wine club, and sicne then FI and I have hung out with her and her husband quite a bit. I also hang out with her alone a lot and have become pretty good friends with her, but we also like her husband. The last time I went out with her and another lady for "girls night" we found out she and her husband have separated but she said she was hoping to work things out. The night proceeded and she starts flirting with this other guy (who turns out, is also "separated"), the guy pesters her for her phone number all night but she wouldn't give it to him (at least while we were around), I finally make a rude comment to the guy about backing off, friend disappears for a while, and later we find out she went to find the guy and swapped phone numbers. Now he is watching her dogs while she is out of town, and last weekend they went to the mountains together...guess she isn't trying to work things out with her husband anymore!
So...as far as invitations, we had planned on inviting her and her husband before all this (again, we consider husband our friend, even though I have spent more time with wife).I decided I would just send an invitation to her, with her and husband's name on it, and let her decide if he would be there. I asked her if I should send the invite to the place she was staying at, or to her/husband's house and she said the house.
Yesterday I get the RSVP back with "accept" and "2" people attending. Now the invite was addressed to "Friend Last name and Husband Last name" (she never took his last name), not to "friend and guest". So this would make me think husband was coming too. But knowing friend has been out of town with this other guy makes me think husband and friend are not trying to work things out and she might be trying to bring this sleazy guy to my wedding (who I was rude to which would even more so be awkward). It would also be awkward because since FI and I like the husband, its really awkward that she would be bringing this guy instead of husband who is still trying to get back together with friend.
All that said, if she did say she was bringing sleazy guy, I probably won't do anything about it except cringe and hope he doesn' tremember I was rude to him. I sent her a FB message asking if her "2" meant husband was coming or if she was bringing someone else, and just to let me know the name so I can make the seating chart.
Just thought I'd share the awkwardness with people who I can't get in trouble for gossiping with