I'm not very experienced when it comes to guys but, from my late-teens onward I'd read stories on the walls in cottages and got worked up by them, masturbated over them, and when I encountered guys with their cocks out, hard, stroking them, THAT definitely excited me too.
The problem is that I don't FANCY men at all, whereas I find the majority of women appealing in one way or another, but whenever I saw a guy with his cock out, wanking, pissing, whatever, but deliberately showing it off for my attention, that definitely did, (and does), do something to me, and gets me hard.
I've always found TVs a turn-on. I love the classic sexy undies that they like to adorn themselves with, and it didn't seem to matter that they had a cock rather than a pussy framed by the suspender belt straps, the sexy lingerie still kept sending the same messages to my brain and turning me on. So I was ok with a 'sexy girl with a cock', but couldn't imagine ever getting excited by a man.
So, when I got chatting to this guy on-line, and he said that he loved to suck cock, and loved to tongue male arse, I was tempted, because I'd found it an intensely pleasurable sensation in the past when I had a gf that did that. I figured that, even though I knew that I wouldn't fancy him, it might help break down my inhibitions about the fact that I was with a GUY if he was happy doing the cock-sucking and rimming and didn't want anything in return.
However, how it turned was a bit different.
I went to his house and rang the doorbell. When he answered the door he was older, and uglier, than in the pics he'd sent me, but I figured that I should grasp my opportunities regardless, and went in.
He took me straight to his bedroom with no small-talk, sat me on the edge of his bed, took his cock out, and pushed it straight into my mouth. His hands went 'round the back of my head and he held me there firmly while working his cock in progressively deeper and started fucking my mouth while giving me instruction on how he wanted it.
After a while he released me and had me strip off, get up on all fours on the bed, and spread for him. He got behind me and started fondling my cock and squeezing and pulling on my balls, working me over until I was hard, then he started on my arse, and it DID feel really good to have his tongue working its magic back there. After a while he paused and I looked around to see him squeezing some lube onto his fingers and when he resumed his attentions it was with a finger going deeper than his tongue had reached, and it STILL felt good, and my cock was fit to burst!
Then, (inevitably perhaps), he shifted his position again, took hold of my hips, and I felt my arse being stretched far more than before - and it hurt like hell!
Realising that he intended to fuck me, I looked back, saw that he had no condom, and was really hurting me, and shoved him off.
Thankfully he didn't get 'difficult', but straddled me as I lay on my back and pushed his cock back into my mouth, then held me there while he fucked my mouth 'til he came.
As soon as he'd finished he told me that he had to go out, so I left, and drove all the way home with the taste of his cum in my mouth.

The funny thing about it was that, when I thought back over the experience, it excited me! I wanked off countless times afterwards remembering how he'd used my mouth so roughly and made me swallow his spunk.