Actually Razor,

What I liked about the ending is the fact it gives the reader pause to think.
Brian has gone through an experience, endured humiliation, and in at least some manner it has transformed him.
He no longer puts up with crap from the kids.
The exact process and reasons for this change are hinted at but you let the reader decide. You leave them with their minds engaged and maybe a few new questions but that's not a bad thing.
It gives you an opening for new stories or new chapters if you wish, but certainly that's your call. It's the very believable experience and change that impresses me. Like you I'm a little skeptical about the " Rape me and I'll cum all over you" story line. It takes real skill to pull that off with any credibility and it's been done to death.

Yours
Mad Lews