Not sure where to ask this, but I'll try here. FI is at his bachelor party weekend and there are some guys celebrating with him who were not invited to the wedding (this was not our doing, this was the GM). One of them recently became a roommate of the GM where FI is crashing this weekend. In all of the many guest list discussions FI and I had, this guy NEVER came up. I just met him once many months ago and I believe that was the first and only time FI met him, too. They sometimes interact on FB, but otherwise, he's more of an old friend of FI's GM than a friend of FI.
FI partied with this guy and his other friends last night and now is very firm (stubborn) about inviting this guy to the wedding, 3 weeks from today. He reasons that 1) we have space in the guest list since people have RSVP'ed "no", 2) he will come, and 3) he's a good time. The GM who is the guy's roommate asked FI "a while back" if the guy could come and FI said he wasn't sure, we'll see, etc. but FI never mentioned this to me. Last night the guy asked FI if he could come to the wedding. FI told me today he would have invited this guy (and other's in this social circle we never discussed) if we would have had space on the guest list, but again: this group was NEVER mentioned and there were MANY people much closer to us who we were not able to invite due to budget restraints and it is now too late to invite because they are "B-list".
We don't have minimums on our venue, our guest list is really close to exactly the # of people that we wanted to have, and there are many people who deserve to be at our wedding more than a guy we've just hung out with once and happens to be friends/roommates with a GM right now. Not to mention that this guy also has a serious gf, who would need to be invited, too. And that others in this social group would wonder why they weren't invited, even though some have known us much longer. In our discussions/arguments about the guest list, I've stressed that I want everyone there to be special to us (or we're morally obligated to invite them, e.g., some family members). We don't need warm bodies to sit in seats. I feel it's rude to our friends who did not make the guest list to let some random guy come to our wedding, eat our food, and drink our booze, just because he was rude enough to ask if he could come 3 weeks before the wedding. FI is hanging out with this guy all weekend and is being uncharacteristically hurtful to me today, and he thinks I'm being ridiculous and asks "what's the harm?" I've told him everything I've said here, to no avail. Help me - do I stand firm on this or let it go? I'm also afraid this will spread to other guys he's partying with this weekend who were also not invited...Again, the GM did that, and by the time we found out, we couldn't invite the uninvited to the wedding (budget) or uninvite them from the bachelor party (rude).