My foot cramps too because I curly toes when it's really good and the after climaxing I relax and sometimes get a major foot cramp haha no big deal. If he had an electrolyte imbalance the cramps wouldn't only occur after sex. :)
no its a severe body reaction to sex. My bfs leg has a charlie house when he gets to aggressive its funny
He may be low on potassium, or just be in one position too long.