So, I asked her if she wants more underwear for her son, since I have a few bikinis, string bikinis and thongs that I have ordered over time, that were either too tight, or did not fit well.
She said, "Yes, he'll take them."
So, all in all, I gave her 20 pair of men's underwear- bikinis and thongs. I told her that whatever he doesn't want, just to send them back and I'll hold on to them.
I even threw in a couple of panties that are passable as men's bikinis and low-rise briefs.