"AIO, Am I Overreacting for Getting Upset About My Friend Using My Toothbrush?"

So, last week, I had a weird incident with my best friend. We were hanging out at my place, and after a long day, we decided to grab some pizza and just chill. At one point, I went to brush my teeth before bed, and I noticed my toothbrush was out of place. I thought I had just left it in the wrong spot, but then I realized it was wet, like it had been used.

I immediately confronted my friend and, to my shock, they admitted they’d used it because they forgot theirs. I was totally thrown off and tried to keep my cool, but I couldn’t help but feel grossed out and honestly, a little betrayed. I told them it was a huge boundary for me, and they apologized, but it felt really weird.

I’ve tried to shake it off, but I keep thinking about it. I get that it’s just a toothbrush, but. it’s personal, right? Am I overreacting here? I know we’ve shared stuff before, but this felt different. Is it unreasonable to be upset about something like this?

TL,DR, My friend used my toothbrush without asking, and I’m really bothered by it. Am I overreacting, or is it reasonable to be upset?