Am I required to have sex with my gay friend?

Your not required to have sex with anyone.

You are not required to have sex with anyone if you don't want to, even if you're married.

He's not much of a friend, or boyfriend, if he keeps trying to manipulate you into doing things you feel uncomfortable with.

You'll have to remind him, nicely, that you aren't interested in sex. If he wants pics of your genitals tell him "no." And if he sends you pics of his just delete them.

If he still keeps harassing you about it, then I'm afraid it will be time to move on. You shouldn't have to cater to anyone, especially if they make you feel uncomfortable.

Yeah, right...I call bullshit not just on your story, but on the claim that you actually have a gay friend.  Someone as clearly homophobic as you wouldn't be friends with anyone who's gay.

Why not just have sex with him?

It's nice to have sex with people who desire it -- be a nice guy and do your friend a favor.

Stop obsessing!

Seriously,  if that one person can do all of that I urge you to never walk into a car sales yard,  you clearly are not a very strong person. 

Better get on with it before you get called a homophobe

Time to cut him off. He is not showing you any respect. He has no boundaries. He lacks judgement. And if he threatens to blackmail you just say you lost all your money and let him send what he wants to send. But matter of factly tell him if he does do that you’ll then sue, get a restraining order and force him to register as a sex offender for life. In fact if he does threaten you or keep making these comments - just get the restraining order. That way if he does anything - you have a record.

Is this really a question?

If it is, you need help.

He just want to suck it. Throw the poor fool a bone.

If he's that good at manipulating you, sounds like a good time.  Try it - you may like it.