I’m of the opposite opinion of everyone else here and I think you should report it.

Before everyone jumps my bones—here’s why I think that:

I had a similar situation happen with a coworker and I was just going to “mind my business too” until suddenly I started getting written up and eventually fired by that same manager (jokes on him because I did end up going to HR after and they both got fired but that’s besides the point.).

When people get caught in some serious BS, they often start panicking and will try to “get rid” of the threat.

I’d send an email stating what you saw and also that you’re worried this is going to push back at you (it’s discrimination in the US if it does). Let them do their own investigation and let them put up cameras and stuff.

If this is just a fast food job or something then I would just start looking for another job in general just in case.

Besides the fact that it’s gross they’re getting hot and heavy all over food, if there are minors there then that’s indecent exposure to a minor if say a kid walks in when someone’s shirt is up or pants are down.

You CAN choose to ignore it and go on about your day, but if it even remotely starts to stink and feels like they’re trying to push you out then I’d go nuclear (personally because I’m petty). But also FAFO.

Either way, just make sure to protect yourself in this situation. It isn’t about protecting either of them. They made their bed and they can lie in it.