[He leans forward just enough to brush his lips over hers again, nuzzling her nose a little with his. He's pretty sure he understands why she feels so pressured to rush this, and he wants her to know that that's the last thing he wants.]

Your body will get used to it the more we do this. It's still something new for you, so it needs to adjust. Nothing wrong with that at all.

Besides...

[And now he leans in to nip just a bit at her neck.]

The more we practice, the easier it will get.