The third base is anything that involves the genitals but falls short of full penetration.
But, if she is not comfortable with her partner it isn't going to happen.
You don't even have to be the one to move your lips toward his.
We also call this base the sensual touch.
Watch this fun video where the women of the view chat about laughing during sex! Generally speaking, we consider intimate touching second base.
This baseball metaphor has often been used to describe relationship bases, which are stages of physical relationships.