grabbing another's chin
A character touching another character's chin, or more generally the underside of the bottom jaw, with the apparent intent to move, immobilize, or express control of it.
Situations without such intent may be better described as stroking another's chin.
For characters grabbing or touching their own chin, see finger to own chin, hand on own chin, stroking own chin, or head rest.
See also
This tag implicates hand_on_another's_chin (learn more).