Thinking about blasphemy (:
Thinking about being a good son of god and being oh so pent up as a result, not even able to touch myself because I'm a good priest and know it's a sin and a vice.
Thinking about a demon showing up and teasing me, maybe I summon it on accident without realizing and he knows exactly what I want. Maybe he pulls out his cock and strokes it in front of me and tells me I can have it if I'm good for him. He'd convince me that it was ok, it wasn't really a sin, just experimenting just once. Then he'd shove his cock down my throat and fuck me mercilessly, teasing me as he notices me getting harder and wetter by the second. He'd tell me exactly how to touch myself and I'd moan desperately around his cock. He'd stop before I could cum though, pulling me off and bending me over and shoving into me, fucking me through orgasm after orgasm until I'm begging for more, renouncing my faith if he'll just keep using me like a whore. He'd laugh, tell me about how he's going to have every demon in hell use my holes, how I'm such a perfect slut and it's a travesty I hadn't put my tight holes to use sooner. That God made me to be a whore and this is where I belong.
Or, alternatively, the demon pretends to be an angel and has me worship his cock, reminding me as I lick and suck at it that I can't touch myself. He's gentle, guiding me on what to do and telling me how good of a boy I'm being, such a loyal servant. He asks what I'm willing to do for my faith and I tell him I'm willing to do anything. He makes me take my own virginity on his cock, having me sit down on it and ride it. I'm not allowed to touch my aching tdick the whole time, and he refuses to touch it himself. He lets me fuck myself stupid on his cock before rolling me over and slamming it into me, laughing about what a stupid slut I am to fall for that, how he's going to use me over and over again and that I belong to him now.
Either way, he fills me with his seed and leaves me dripping on the church floor, whimpering and jacking off to the thought of being used again.