And there I shut her wild wild eyes With kisses four. (lines 31-32)
Finally, the knight is doing something for himself. And what is he doing? He's "shut[ting]" her eyes. Maybe the "wild[ness]" in them was starting to creep him out, or maybe he's just trying to calm her down.
And there she lulled me asleep (line 33)
Out of context, this sounds like a very loving, maternal scene – like a mother rocking a baby to sleep. Like some of the earlier passages, this line makes the knight seem passive. The lady is doing all the work, and he's just following her around and falling asleep in her "elfin grot."