So I have known this guy for several years. We worked together and were basically lunch friends.. nothing more.

But here lately we have been hanging out a lot and it has become friends with benefits. He is really cute and I have feelings for him... but I think it is just friends with benefits... I guess I need to leave him alone since feelings are now involved... ugh.

If he doesn't share the same feelings for you, I would suggest letting go of the benefits part, because you only risk getting yourself hurt if you don't.

That was easy, as you already know what you should do. Its not unusual for friends to develop lust for each other, and lust can lead to some rather intense feelings. But FWB, is great until only one partner starts getting feelings for more, and the other doesn't. Messy messy.

But what's worse is when one partner starts lying about their feelings to keep the benefits going, and the other gets strung along. That's a disaster.

....I guess I need to leave him alone since feelings are now involved...ugh.
You are correct.

Friends with benefits is no ties, and no feelings more than friends

If you reap the benefits before its official its bound to not end well... Just saying.

Just walk away from the relationship. Friends with benefits never works out for the best.