Okay, so FI and I are having a bit of an argument on whether or not to invite a few of my cousins. I have 5 cousins on my mom's side who I'm not really close to (and 3 more who all have families and I'm really close to). I hardly know these 5 at all. My uncle had 3 of them with one woman, who he then separated from when they were fairly young and then 2 more with another woman who he also separated from when those 2 were young. One of these cousins "B" has been trying over the past few years, to get to know us again, he's been coming to Christmas dinners and other family gatherings when he can (they all live about 2 hours away from us). Occassionally, he'll bring one of his siblings with him but not very often. My uncle has visited a whopping 2 or 3 times over the last 15 years and brought his other two kids with him recently.
Anyway, all of these kids are adults now (early to mid 20's). One of them was married last year and none of my family (including my immediate family as well as my other aunt and uncle and cousins) was invited to her wedding (no big deal, we just figured it was a small wedding). I know 1 of them is engaged, 1 is married and 1 has a steady boyfriend, not sure about the other 2.
FI doesn't think we should invited them at all or else he figures we should just invite "B". But I'm thinking I should invited them because they're family. And if we do invite "B", I think it would be rude not to invite my other cousins. I also think it would be rude to invite the other 3 cousins and their families that I am close to and not these cousins. We're all friends on Facebook, even though we don't really talk. FI says that he's got lots of cousins on his side that he didn't add to the guest list. I told him that's fine, it's up to him. His family dynamic is a little different than mine anyway. He also says if I don't think they'll come (which I don't, aside from maybe "B"), why waste an invite...I tried to tell him that's not how it works

So any ideas? I should probably just invite all of them right?