How long has he been with you? Sounds like he is not fully comfortable yet

I’d just let him lick. It sounds like a grooming behavior, he wants to be near you.

6 weeks old is so early to get a lop, mine weren’t even weaned until 6 weeks. He definitely is just adjusting to his new surroundings and you, especially because he was given to you so young. Attempt to pet him, but if he runs don’t chase him because you’ll look predatory and he’ll end up being afraid of you. I have 13 week old Hollands, and Asriel was extremely anxious for the first 3 weeks to a month. We’ve had them about 7 weeks now. Asriel would always stay huddled in the back of the enclosure while his brother just wanted to be out and about for love. Now that Asriel is used to us and our routine, he’s ALWAYS begging to come out and run around (he’s so athletic and is basically a blur). He’s still not much of a petter until he’s gotten all of his energy out, then he’ll flop on the floor and get pets for a few minutes.
Some bunnies are just more anxious than others. He could even take longer than a month to fully trust you. We’re learning that with Asriel. He’s comfortable enough to run around and explore everything, but he’s still incredibly anxious over different things. Just be patient and give him time, like I said, especially because he is so young.