If you want to get lucky, you have to get the positioning right and you gotta stretch first. No one wants to have to stop because they are too tight! Use this stretch next time before anything gets rolling to stretch yourself out and get that low back ready to do the deed!
Start on your back with your knees bent. Keeping your stomach tight as you move, bring your knees up into your chest and giving yourself a little overpressure with your arms. Bring the legs back down into a bent knee position again and repeat for 30 seconds to get yourself nice and loose for the night ahead.