romance between maid of honor and best man

Maid of honor is asked to go check in on bachelor party.
She puts on some kind of disgue and ends up sleeping with the best man.
I also remember somthing about an animal auction for chartiy where he ends us with a bunch of animals because he was trying to impress her.

You are describing The Dare by Elda Minger. Is this the book you had in mind?

Yeah, I think that is the book I'm looking for. I have described this to so many people over the years and everyone just looks at me like I'm crazy. Thanks so much for your help.