Sticky situation at work with coworker, advice?

[Alottosay]

I just started a new job 4 months ago. I started working with this guy. He's very funny and I enjoy talking to him. Some time after talking, I developed a crush on him. Did not want it to turn into anything. Didn't want him to know, just a secret crush no harm done, right. I guess I did a horrible job because he called me out on it. Things were all good, but he started to flirt with me, and last week it was in a sexual way. Really implying he has been checking me out. I have a little devil on my shoulder who have entertained the thought, but reliable little angel knows its only trouble. I'm going to listen to her. I don't want to make work awkward. How do I tell him I want the flirting to die down.

[Guy13]

Distance when not forced to work on something together. Hope you are able to move freely…. Always have another in view or ear shot. It’s work…. Never walk in together…meet for lunch…sit beside etc. it will take a month or two to believe you AND did I do something conversations. “I’m just trying to work while at work” was what I said….

[In_Trance]

You can't fuck around; tell him straight up and be perfectly clear. If he doesn't stop you'll break his fingers. Otherwise, he'll think you're playing hard to get

[JakeS00]

You could say how you feel, and how you don't want to do so much flirting. I would listen to that angel on your shoulder.

[maximumpower]

diffuse the situation by not playing along. keep communications - verbal and physical - professional and appropriate for the situation.

[slatyb]

“Let’s keep it professional.”