I think there's other stuff going on here. The dp obviously feels a bit sidelined. It's difficult to get his head around his dp not only going back to work, but then having 2 nights out with them already this year (it's only March). How strong is your marriage in other ways, OP. Would you say you feel close to your dp? Does he feel very secure about you?
My dp doesn't go out that often with work, but if he did, I'd be a bit
too. Partly the money being spent, partly jealous that I'm not out, partly worried about 'other women', partly sitting home alone whilst my dp is out having fun. And yes, whenever I worry about my dp, it is more about other women throwing themselves at him, not the other way round. I don't like the idea, even if he doesn't do anything with them.
I think you can choose to 'make a point'. But if your marriage is about that all the time, it's not going to last very long more. You wouldn't like it if he did something that made you unhappy just 'out of principle' (what is the principle anyway?). The strongest marriages are about acknowledging each others' weaknesses/ insecurities, bearing with them, having compassion, and meeting each others' needs. If he never let you go out, that's one thing, but I think if he's asked nicely in this one scenario, that's another thing.
I'd say, "I really want to go, but if you don't want me to go this time, I won't go. However, I will be going on the next one."