While keggle contractions are an interesting sensation, my real fix is finding that special someone who's the perfect fit.  A few years back I watched a NOVA PBS show on long term space flight. There was a segment on whether it would be feasible for man to travel and reproduce in space. This couple volunteered to go through a whole body CT scan while he was inside her. The purpose was to see physiologically whats going on during intercourse. I found two things really intriguing about the segment;

1. They had to remain motionless during the CT. So here's this guy, inside his girl. They can't move, but the goal was for him to stay erect. No pressure.

2.  The resulting images were amazing. As rigid and hard as a penus can be, once inside her, his penus conformed to the shape of her vagina, not so much the other way around.

In the end - you find that someone who is the perfect fit (and I have!) and keggle muscles become somewhat irrelevant.  The only challenge (and I guess it's not a bad one ) is the number of people you need to be with before you find that completely mind blowing physical connection. Lucky for me it happened early on, with chemistry to boot!

We now return you to your regularly scheduled OP topic ...