Watch some bill hicks videos
If i was you, and someone asks you about your penis size, just say something along the lines of "yeah its small and her vagina was so saggy that i had to fuck her in the arse" be crude and not give a fuck as much as possible, and people sense this and go away.
Yeah certainly turn the tables on her if she is doing this, she sounds like a nasty piece of work and its best to remember the red flags and stay away from women like her.
I had a fuck buddy try to embarrass me in front of a whole club by saying i couldn't get it up, which was true but it just backfired on her because my reaction was along the lines of "i couldn't care, i couldn't get it up because you are revolting"
Along those lines, we have all been there brother.