While he doesn't say they're mean, he does complain about being ignored. People will say hi, ask him general questions about SS or about trips we have planned. Sometimes he's drawn more into the discussions, but sometimes that's it. He complains about that. He also complains how they talk about people or events he's not familiar with.
He probably is jealous of how happy I can seem around them. He's jealous that I seem to have good relationships with my nephew and nieces, but don't have much connection to SS15. Anyway, I've tried to draw him in to conversations, but it's like trying to push molasses up the hill.
But I think he's also jealous because of what I have. He's shared before that he's always wanted to be part of a loving family. It's not something he's ever had. I think he really, really wants to be a part of mine. But he doesn't know how.
Ding, ding, ding! I think you've figured out your man.
The way I see it, aside from his insecurities and jealousies, his thinking is overwhelmingly negative. He's so caught up in feeling inferior, aggrieved and slighted that he doesn't see what's right in front of him: he IS part of a loving family! He has you. He has his son. He has your extended family. He's so preoccupied living in the past and wallowing in his internal pity party that he can't enjoy a real family party.
On the other hand, your husband's expectations are unrealistic, as he probably envisages some sort of Hallmark movie moment where he's adored and receives abundant praise from your extended family members, instead of just enjoying the general togetherness, even if it means hearing the same old humblebrag from a brother-in-law. Oh, and here's the other thing: your man probably has no idea that other family members are trying to impress HIM with their stories. He's too insecure to realize that maybe somebody else might be envious of him (he married you after all . . . ). Instead, he feels aggrieved because the story isn't about him or something he already knows.
If your husband is upset about not going to parties, then he should host one! It wouldn't have to be a big to do--how about an intimate one with three or four family members, friends or neighbors? A kick-off-the-summer, informal get-together. Make it fun, with cooling-off watermelon, a signature cocktail/mocktail, a viewing of a seasonal sporting event, whatever. If a "dinner party" is too daunting, make it cocktails or tapas.
The thing is, pwBPD are generally all take and no give, not just in relationships, but in everyday things like daily conversations and socializing. Your husband probably thinks the problem is with how others percieve him and treat him. But it's all in his head, due to his negative thinking. If he's desperate for connection, he needs to turn things around, stop being so passive and expecting people to always come to him, and start reaching out. (A fear of "rejection" might prevent him from extending invitations, but hey, people are busy, he just needs to be persistent.) Moreover, he can't expect always to converse about stuff he likes; he could open up a little and at least pretend to like what someone else does. Conversation isn't only about talking, it's also about listening. And life isn't only about doing stuff you love, but about doing stuff with the ones you love. That includes family get-togethers. Two people are a family. So are three. So are ten. For me, a "quorum" for a "party" is three.
I know, you can't force your husband to turn around his negative thinking. But maybe you could remind him: My darling, you ARE part of a family, this one. We love you. Of course people want to see you, and you're always invited. Yes you might have to listen to my brother's bragging again, but that's only because he's trying to impress you. Here's an idea, let's have some family over at our place later in the month, when SS15 is around--let's invite uncle and cousin. We could stream that new crime special together and serve up themed appetizers. Or we could watch Formula 1. That would be fun, right? Etc., etc.