Having thoughts about coworker (who has a BF) every ten seconds

Not always sexual, but very often sexual. Is this just “human nature,” or is this problematic where I need to slow the fuck down and stop? Seems as if my brain won’t shut up.

We are great friends and like each other a lot and have a lot in common. We’ve never seen each other outside of work, but one side of me is even wondering if she may end up cheating on him with me; she can tend to be kind of flirty at times (probably not, but idk, she said she’d cheated on a past boyfriend of hers—some of her scruples are kind of questionable tbh but I still like her).

Can I control this while still being friends with her?

 

As I said before, we’re only friends. And this is a lonely city to live in so I’m thankful for her friendship and am perfectly content with keeping it as just that, despite a man’s feelings still being what they are, they can still accept reality. In fact the boyfriend is the only reason why I DON’T do that (actually act on my emotions). But even if she were single I would be smart enough to take it extremely slow.