Fair enough
If your wife doesn’t like it, that settles the matter, IMHO.
I throw a backyard kids party every year and invite everyone I know who has kids, which means it’s a very random group of adults who I know from every type of group. I usually think beforehand of different connections I can make between them based on what I know of them, and try to tell them the connections during the party.
I hooked up my neighbors from when I was with the family who lives in their house now. On two separate occasions there have been people who were co-workers both get invited. I hooked up my cousin’s husband who loves vinyl with my brother’s friend who also loves vinyl, and another guy who loves the same band. Parents who live in different school districts but their kids end up on the same baseball team. People who are in the same profession.
It’s a fun challenge to the host to match people up!
Personally, almost 100% of the friends I’ve made as an adult come via friends-of-friends that I met at parties. I’m talking people who are now CLOSE friends. It’s pretty awesome!
One of the funniest inadvertent lines a friend ever said to me came from a mixed party. She worked with me at the campus radio station when we were in college. The radio station people were very into hallucinogens at the time. She was also an LGBT activist and a bunch of her friends from that group would be there. It was a Halloween party where my group would be tripping.
She said, “don’t offer acid to any of the other guys. My gay friends are really straight.”
It’s just something she heard once.
Usually the trick to having it go really well is to introduce some of the members of both groups to each other ahead of time. Not the whole thing, but just a few really social members. That way, as conversations naturally arise, there’s at least one person who knows someone in the other group besides you who they can talk to.
As in straight-edge?
I’ve been a guest at parties where I didn’t know anyone other than the host, and also hosted parties where certain guests didn’t know anyone else. Some of my friends are perfectly happy with meeting new people and making new friends. I invite whomever I want to come, and then let them be the grown-ups and decide for themselves whether or not they feel comfortable showing up. As long as you don’t act offended if they decline, it’s all good.
Yeah.
They get to meet one another, which means that they might get the chance to make friends with each other. Or they might not.
Just as they might spend most of the party talking to each other; or say ‘oh, hi, nice to meet you’ and then spend their time talking to somebody else.
I figured out a long time ago that not everybody I liked was going to like each other, and not everybody who one or more of my friends liked was going to be somebody I liked. But they also don’t line up neatly according to in what context I originally met them.
It’s certainly true that unless your spouse is going to be out of town anyway (and you make sure to clean up before they get back), giving a party that one’s spouse doesn’t want to have would be a problem in itself.
Meh. I never did.
I don’t think it’s necessary to give a pre-party before the party.
I went to one where two people who shared a birthday invited their friend groups, which didn’t have a huge overlap. I met my wife there.
Not really a pre-party, but more like if I was trying to merge two groups, I’d usually invite the more social people to go out with the other group and me a few times before just throwing a party.
That said, just throwing a party doesn’t require that- we’ve thrown some that were my wife’s friends, my friends, and work friends of both of us. They all got along famously in fact.
The key thing to remember is that if one group is friends with you, and so is the other, there’s a good chance that whatever they see in you, they’ll also see in the other group’s members. Sort of a associative property of friendship, I suppose.
Went to a wedding once where the bride’s side were all hip, liberal, younger intellectuals. The groom’s side were … not.
Someone thought it’d be lovely to mix the groups ABABABAB at tables for eight. One of the coarser guys at our table started some “Good Ol’ Boy” sexist/racist humor, so Duchess Deborah (seriously, she’d just gotten engaged to a European Duke) brought up that she was reading Proust. Stephen (a journalist for U.S.News, posted to the middle east) started discussing “A Remembrance of…” and I interrupted with “Actually, in the original French, the title is À La Recherche du Temps Perdues, giving more a sense of searching through one’s previous experiences, a more active task than just sitting around thinking…”
The groomsmen just glowered… I still feel bad for tamping down all their joie de redneck vivre.
I attended a wedding where the bride had a masters in a science and the groom was touring with rock bands and making a good living doing it.
I too was curious how this combination was going to go off, but it worked beautifully. The science nerds were fascinated by people who were so loud and unregulated in their everyday ways. While the music types were stunned in a more, ‘But, like, how do you know all that?’, kinda way. Each group seemed sincerely interested in the logistics of the other’s lives. “How many cities? In how many days?”, “You went to school for how many years? Seriously? How’d you do that?”
(I think political opposites would have been much worse!)
It’s great that everyone was sincerely interested in learning about a very different group.
Maybe that’s the trick. It doesn’t matter how many groups are at the party, as long as everybody’s in the group of “people interested in knowing people who are different from them.”
And anybody not interested in knowing people who are different from them probably doesn’t know me well enough to come to a party I’m giving, anyway. 
And I don’t want them as friends anyway.
Are they the people wearing super hero tights and carrying light sabers?
Most of ours were written s-f, not graphic novels or space opera.