The Negative kind:
1) a guy who has really nice hands and looks like he should be amazing at fingering but he isn't because he:
a) doesn't go deep enough
b) doesn't go hard enough
c) just doesn't understand how it should be done
The Positive kind:
2) a guy who, from the look of his hands, that are generally small or with small fingers, shouldn't be good at fingering but he is because:
a) he plays guitar
b) he understands that just in-and-out isn't fingering
c) he has nice arms

A casual invitation / threat used by an individual that is not afraid of fucking someone up.