I have feelings for my married best friend and want to pull away.

Talking to him about your feelings doesn't seem like a valid option because he could break his loyalty and damage his marriage, and you don't look like you could settle on being his mistress.

Neither is stop seeing him due to your close relationship with him, both professional and personal.

Why not get a grip on yourself and stop felling that way towards him when your both together? How did you let it come to this?

Whether or not you should talk to him depends on asking yourself these questions: 1) Do I value and want to maintain the friendship with him+his wife? 2) even though I might not be able to accurately answer this now because of being clouded by my emotions, nonetheless, can I see myself ever being just friends with him, and satisfied with such a connection? 3) If I talk to him is my REAL purpose to make these feelings go away or am I somewhat hoping he leaves his wife for me?

It also depends how mature/level-headed/understanding the 3 of you are. I was able to salvage a close friendship of 2 years when the girl developed strong feelings. Compared to your situation she wasn't married nor did we work together but the connection was just as profound. She confessed, we both knew it was a no-go, and so we dialed things down over several months. We're still friends today, only difference is the interaction is every month or so instead of everyday, but strangely enough that hasn't hindered the friendship.

Sometimes it's helpful if you develop some sort of code/reasoning to determine if you should keep in touch with someone. I used to be a person who made no efforts in keeping people around until my dad learned of my childish ways and said, "don't push away someone who's sincere. they are a rare breed" and it's been my MO ever since.

I would go with honesty. You are not the first and not the last one in a position like this.

I just know that if I was in the shoes of this friend of yours, I'd much rather have all the cards on the table. I'd rather know why a (former) friend is not a part of my life anymore.

Regardless, whatever you do I think you need to keep your feelings to yourself, he is married after all. Just spend less time with him.

This is a tricky situation. I've had this happen before, in your best friend's position. He confessed his feelings for me, I was married at the time. It was... difficult. I wasn't going to leave my (now ex, thank Jibbers)husband for someone else. It ruined the friendship. It got awkward and I just couldn't be around him anymore. Obviously, our situations are different and involve different people and a lot of variables, but sometimes a perspective from someone who's been through the same thing can help.
I'm sorry to say, if he was also in love with you, he more than likely would've left his wife to pursue you already. And even if he did feel the same way, do you really want to be the cause of his divorce? Statistically, there's a very, very tiny chance that a relationship like you two would have would ever work out. When someone leaves a marriage to be with someone else, it very rarely lasts. There's just too much emotional baggage that they aren't given the time to deal with.
Is the very small chance that he'll reciprocate worth the very large chance you'll ruin at least one, and probably both, of your friendships?
My advice to you would be to stop spending so much time with him. I realize he's your best friend and it will be hard, but you already work together and will see each other there regardless.
I see that you said you know that it's love and not just infatuation. I'll trust you on that. But you know, love isn't always all-consuming. It takes a lot of nurturance to keep it thriving. Maybe if you get a little distance, it will fade some. It may not ever go away completely, especially while you still work together, but it will get easier. Though, you might eventually have to get a new job if you can't stand being with him and not be /with/ him.
Lastly, I just wanted to say a lot of people would act impulsively on their feelings with little regard for anyone else involved. I can tell you're putting a lot of thought into this decision and I admire you for even posting here.

I know u've said ur best friends etc but for a couple of adults ur spending way too much time together even if its because ur workmates.In my experience when ur always together with someone if you didnt have feelings before blv me they are just around the corner.
I suspect this guy feels the same way.Tell him how u feel...its a win win for you no matter how he will answer.

Has he ever eaten you out yet?

Everytime you think of him, eat a chili.