I can see how that would be a problem, unfortunately, I'm not a boxer expert.
Maybe try a different kind that are made to stay closed better.
Hell, I don't know what to tell ya, but I was thinking about the buttons and I would think a button in that area would make your friend a little uncomfortable.
I'm a girl, so what do I know
Sorry I can't help on this one mrhunt, but good luck with that ;-)