Open marriage here:

Any time a hookup says they don’t use condoms, it’s a huge red flag. Always ask a partner in a neutral way about condoms to force them to the binary answer.

Example: would you like to use condoms? Do you use condoms? Do you bareback?

If they don’t answer straight, or say they prefer not to use them, move on. It’s really not worth the hassle of even curable STDs (pregnancy fits here), especially if you’re not on Prep. I would never bareback with a stranger without at least using Prep.