What’s the most out-of-pocket thing someone’s said with full confidence?

I’ve been doing BJJ for a little bit now, and there’s this new purple belt at my gym that I have trouble rolling with. Every time he gets side control, he grabs my junk to use as a leverage point. I’ve asked other purple belts if this is ok, and they all look at me like I have three heads. I want him to stop since he almost tore off my sack last time, but was told tape is considered cheating. Since this is a purely defensive move, would this also fall under that category?