I think your very best bet is to wear your pants (preferably with other garments like a shirt! ) and go have a pleasant evening.

Check out how everyone else is dressed and use that to base how you should dress next time.

If it was me, I would go in a kilt.

But I would be wearing a hand sewn wool tartan one and my tweed crail jacket to go with it.

If I didn't have these to wear I would wear a nice sport coat and pair of slacks (with shirt and tie ) and check out what sort of kilts (if any) were worn for next time.

What you don't want is to wear an outfit that doesn't measure up to what the membership of the Society is wearing. Better a nice trousered outfit than a poor kilted one.

Have a great time

Cheers

Jamie