Skellig finds it difficult to sit still, like this - after all, everything he wants (and she wants him to do to her) is literally right there.

So he allows for that moment of adjustment. Briefly, before he shifts his mouth and works to pleasure her as he knows she wants (needs) him to do, to aid her in being ready for him. This is quite different from the times they've done this before, but he isn't about to complain.

Quite the opposite, if anything.