During sex, the male is on the female can be many different positions, and while he's in her, he holds her hands/arms/or anything else to keep her down while he's busy fucking her, then says something like: "I have AIDS," or "your best friend was better," etc. She then tries to get away as fast as she can. As the female is trying to get away, her frantic movement is making his dick go deeper inside her, at a faster rate.
"Last night I tried the whole 'Bucking Bronco' thaang with my lady. I know that's terrible...but, DAMN! It felt so good."