Heck it goes both ways. I was pinched on the butt by a girl in high school as I walked on stage in a play. Had no idea how to handle it. She was out of my league in cuteness, popularity, and coolness. I was kind of akward back then. Played it cool and ignored it. Later she pinched me on the butt again when I was walking into backstage restroom. And she asked if she could “hold it” as I peed. I told her no because I was likely to get too excited too pee and if she moved her hand I might cause a mess. She laughed and approved. Strange girl. Have no idea if she was intersted in more than joking around. But yeah it was not approriate and made me feel akward. But also it helped me fugure out how to deal with akward situations. I cant imagine wanting to come after her as an adult on her career whatever she ended up doing. That would be just nasty.
She may have experienced holding some creepy grown up man’s pecker, against her will, and was just acting out.
So looking back...I think you might have “handled” that differently.
Sounds like a candidate for the hot/crazy scale.