His wings almost move of their own volition, coming up higher to give her better access to the most sensitive places that bring him the greatest pleasure, his downy feathers on the 'inside'.

(Only SHE gets to touch THOSE feathers in such a way.)

Having her on her back like this beneath him is also advantageous because it gives her greater freedom to let her hands wander, her legs shift to hug the outside of his thighs, all of it feels so very good. And Skellig is not being quiet about it, using the breaks between kisses (when he should be catching his breath) to mutter random words of praise and adoration.