And, secondly, you don't fuck with me and mine.
It's time to bring on the humiliation.
If I was in this situation, some part of me would actually bring up her "Spin the Bottle" story while she was present and we were in the company of S/O AND her fiancé.
And, watch her attempt to explain herself, to all the parties present.
And, once that fun was over, I'd send that "friend" packing.