An invented girlfriend as an excuse to say "no" is in no way LESS of an impediment than an actual jealous girlfriend?
Your partner's ex, your partner's friend group, your partner's life choices are your partner's job to manage.
"Good news, I finally persuaded my fiancée to let me sleep with other people, now we can finally act out all my fantasies about you over Zoom!" Whoa, seems sexy!
"Inside this lady are two bigots, one is capable of acting nice sometimes and the other is not, don't feed either of them with your time, sympathy, or attention."
Wear a seatbelt! Where's your helmet? Will there be parents there? Parenthood requires willingness to say no to lots of fun stuff in the name of safety, there's no time like the present to get started.
All those guides for how to say "I do", you'd think there'd be way more advice on how to undo it.
It's okay if someone you strongly dislike gets an inkling that the feeling is mutual.
Like the creative writing workshop advice goes, if one person tells you a piece of feedback about your story, that's just their opinion, but if ten people give you the same note, there's probably something worth paying attention to on the input side.
"Why is EVERYONE creating so much DRAMA?" -The Hot Mess Who Both Smelt It And Dealt It, usually
There is "what might be technically owed" and "what is realistic and workable now." In general, don't try to extract the former at the expense of the latter with people you'd like to stay friends with.