Rosanne really hasn't put it in too deep in her mouth yet. She is basically only letting the tip in, almost like she is just tasting a sample with her tongue and lips.
"Rosanne," Robert calls her name gently, because his desire for her is building up too quickly and he needs her to give him a release.
But he does not want to do that to her mouth. Robert is still an old-fashioned man. He does not believe in the oral act. Even though he doesn't have any experience in any act, he has only fantasized the traditional penetration.
Rosanne's mouth makes a loud, wet, "plop" sound, like when a lollipop slips out of the mouth. She looks up at Robert from a low angle, lips wet.
"You... you don't have to do this just because I have a reaction. I mean... It doesn't mean I want you to do that." Robert is trying to be polite, but then he worries that also sounds like a rejection.