When a pornstar is unable to
handle a large
cock, especially when the guy is thrusting too deep in
doggy position, she/he starts to move away on her hands and knees, this is known as 'running'.
The blonde couldn't take the deeply thrusting
huge nigger
cock any more, and started to inch forward, yelling, and the director muttered 'she's running' but the
huge black man carried on relentlessly ramming her with his BBC until she collapsed in a whimpering, fetal heap.