Licking their toe

When one is trying to get on the good side of someone else in order to extract a favor or other good from them. Targets of the toe lick maneuver are commonly professors, parents, or significant others.

"I really needed a grade boost, so I was licking their toe pretty hard in the course evaluation."

"Not to lick your toe or anything, but your eyes are like fucking diamonds and your brain is magnificent. Just to be clear, not licking any toes here."