Q actually snorts at that, shaking his head and even petting Wesley's cheek fondly. "Do you even have one lying around?" he asks, amused at the thought of it.

Luckily for Wesley, Q isn't intending to get up to go find any such restraints for him. Instead he murmurs, "Keep your mouth open for me, darling."

Then he's using his grip in Wesley's hair to draw that mouth back on his dick, deliberately going slow to start so the assassin can get used to not having control over the thrusts or speed of the affair. To know to relax and breathe, to accept that Q's in control.