How do I (f39f) tell my hookup (35m) that I made a mistake?

I shouldn't call him a hookup. He's more than that, we care about each other. But he's not my boyfriend either.

Background- I (39f) have a situation with my kids' custody which prevents me from being able to move out of state at the moment.

But there's this a super amazing man that I see from time to time. He (35m) and I go way back to the college days. We were involved a bit back then, he deployed, and circumstances sort of got in the way of any serious relationship. But in recent years, we have reconnected. Now he lives 5-6 hours away, which is why we don't pursue each other seriously. But when he's single we occasionally go on weekend getaways together. The sex is always mind blowing, and he's always a gentleman. Really just a cool, super hot, laid back guy. And our weekends together are some of my favorite memories.

Okay so here's what happened: I just got back from seeing him. It was great, as usual. It was almost time to check out of our hotel and I quickly went to brush my teeth before I packed my toothbrush. I finished brushing, went to pack my toothbrush, and saw that my toothbrush was already packed. OH MY GOD I HAD JUST USED HIS TOOTHBRUSH. I didn't know what to do-i was so embarrassed. So instead of telling him like a normal person, I panicked. I washed his toothbrush with mouthwash and super hot water, dried it off, and put it back on the counter. And then I just acted like nothing had happened.

I'm still so embarrassed. But this brings me to my question.

Men reading this, would you care? Would you want to know? If so, how should I tell him?

Not to be gross but his mouth has been all over me and vice versa, many times. So I feel like it shouldn't really matter. But some people can be weird about toothbrushes. I'm 99% sure he would laugh but... I dunno. Help.