He is a bit frustrated at needing help (this isn't how it's supposed to go), but her fingers feel nice guiding him in, and then he's in and any frustration is forgotten.
John hardly remembers he's wearing a condom at the moment -- it's hot and wet in there, and squishy and... it's hard to describe exactly, but it feels really good. "Oh, fuck," he says, and practically cums straight off the bat. He tries holding it in, and thrusts, once, twice and... he can't hold it in any longer. John cums, filling Rosy (his slave) with his cum (well, filling his condom at least but it still feels that way). "Fuck," he says, and then repeats himself, as he enjoys this pleasure for the first time in his life. "Fuck, fuck, fuck, fuck, fuck, fuck fuck fuck, fuck." It should be pretty clear from his tone, despite (because of?) the word he's using, that he's having a good time. (Even if some part of him is frustrated that he lasted almost no time at all, but there will be time to think about that more later. Right now is mostly pleasure.)