My ex boyfriend once grabbed a bottle of scented hand lotion and used it as lube during sex without me noticing. As soon as I realized what he’d done I freaked out and told him that he couldn’t do that and that it was incredibly unhealthy for my vagina. He told me I was overreacting and that it was fine and when I persisted he told me that he’d had way more contact with vaginas than I did (due to having sex with a number of cis women) and therefore knew more about vaginas than I did.
Apparently living my entire life with my vagina makes me less of an expert on my own body than him. And then when I had a terrible reaction to the lotion and ended up with a vaginal infection because of it he said it must have been something else because it just couldn’t have been the lotion.