So after I got divorced, I had a decent amount of casual sex. I asked every time if they'd been tested lately, their recent sexual history, and used condoms in 90% of cases (almost always on the first time, 1 exception, and 2 later on with guys that became regular things, one of whom was the first exception). Still got herpes from a one time deal I met on tinder and used condoms with.

They all told me they were clean. The life lesson to take away from my experience is, imo, don't take people's word for their testing status. If I could have a do over, I would pass hard on hooking up with strangers (mostly the whole STD thing, but also cause it was never worth it, yay depression), and I'd want a physical copy of test results. I got tested regularly for everything (also the only reason I found out I had HSV since I never had any symptoms), always had a copy on hand and offered it. I think any mature and responsible person would be okay with this, and if they're not, that might be something to think about.