"Red Lining It" is a way of saying that you are driving really fast, reffering to the red line on a car's RPM gauge.
by Icarus0311 October 09, 2006
When you're having unprotected sex with a woman during her time of the month and you pull out to give her a facial and the first line of semen has a red tint due to the menstruation.
I was so caught up in our passionate love making that I totally forgot we'd be Red lining it tonight.
by dvink December 09, 2010