I had a GF that was a massage therapist. She really got into the whole massage thing, and often didn't want to mix in any erotic stuff when she was giving me a massage, we'd save that for later. I'd get a huge hard on while she was massaging me, and it would go away in a few minutes, then I'd get hard again in another few minutes. She said it was fun to watch it happen. But I do remember one time that she was giving me a massage, and I was on my back, naked, no sheet over me, and I did not have a hard on right then. She surprised me by massaging my thighs, and then taking my whole cock into her mouth. The oil she was using was making my skin feel a little cool, and the sudden warmth of her mouth on my cock was such a fantastic feeling that I think I was cumming even before I got hard. I've never had anything like that happen before or since, and it was probably the most powerful orgasm I've ever had.