How we cite our quotes: I cite by line number only.
Quote #1
She looked at me as she did love,
And made sweet moan. (lines 19-20)
These lines are usually interpreted as a sex scene. The knight and the lady here consummate their love. At least, they're consummating her love. Notice that she's the subject in this sentence: she's the one doing all the "look[ing]," "lov[ing]," and "moan[ing]."
Quote #2
I set her on my pacing steed,
And nothing else saw all day long. (lines 21-22)
The knight is so obsessed with the beautiful lady that he spends the day gawking at her. Is this love, or obsessive lust?
Quote #3
And sure in language strange she said –
I love thee true. (lines 27-28)
Again, it's the lady, and not the knight, who's doing the work here. She tells him that she loves him, but he doesn't say a word.
Quote #4
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.
Quote #5
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."