It's fortunate that he agrees. Not that Vex wouldn't have stopped if he asked, but it would have spoiled the moment, interrupted the flow of things. And to some degree, all he has to do is not interrupt.

Vex is happy to take the lead, whether it's initiating the kiss or cleaning Percy to her standards.

To her credit, she doesn't reach for his cock immediately. She goes back to his chest to start working her way down. Picking up where she left off, as it were—and also making him wait as she lavishes attention on every inch of his body.