She sounds like the type who ends up banging the 15 year old in her class

Is it possible John was the only man she had been with up until the stripper? I'm not sure if that's a mitigating factor, but maybe it could be if he wanted it to be.

Give the ensuing events.

In some ways that makes the whole thing even weirder.

Who would possibly think it was "normal" for somebody to fuck a stripper at a bachelorette party?
1.) A complete whore
2.) A very naive fool who lacks life experience under the influence of her party girl maid of honor

You have to be way beyond conventional levels of naive for (2). Because you not only have to be naive enough, in the standard sense, to accept the story that it's "normal," you also have to be sufficiently unmoored to conclude that "normal" is the same as "acceptable."

I also wonder what the true n for this sort of thing is. How "normal" is it really? Nashville has become the bachelorette-party capital of the country in the last few years. The groups I see roaming downtown do not tend to exude an "I'm here for a little chaste fun" air. (Ask the same question for the other sex as well, but they don't seem to stand out the same way.)