When not casting spells, they perform well in other ways.

[He takes his time on Astarion's abdomen, letting his thumbs rest in the divots made by his muscles, his fingers trailing along the curves of his ribs as he steps closer. He puts himself in the space between Astarion's knees, letting his hands rest on them; his eyes linger for only a moment on his arousal before moving to gaze into into those garnet eyes.]

The most intimate magic often requires a delicate touch. Provided that's the sort of experience you're looking for, of course.