[She arches her back sharply as he keeps pressing into her, her breaths increasingly labored; she bites down on her lip and glances down to see that no, he's only halfway in but still feels impossibly huge.] T-trying, but it's... bigger than I'm used to...

[No, she's a professional. Play it up, make him enjoy it. The breathy nature of her voice gives her tension away, but she tries to sound as cute as she can with a huge dick inside her.] Oh, Doctor, your dick's so big and I'm so small... you're going to push me to my limit.