Oh I think you know exactly how the rest of that chat would go...women are incredibly reasonable about such things....
Wife: "Oh, how lovely - you'll have an amazing time - are they nice?"
You: "Yes, all ages as well - some single, some married - its just like going out with the lads, but its girls"
Wife: "Well have a wonderful time. And if you want me to pick you up later, then just give me a call. I don't want you having to wait about for taxis and the like."
*guess we won't be seeing you then*