Generally you continue to pair until you see an ovy or are sure the female is gravid (make sure you give them a break in between pairings) .... As far as how often will they lock.. that is simply a case by case basis .... Some snakes are lazy, some snakes haven't figured it out yet, and some snakes will simply not pair with a certain male or female just because they are not interested .... It ranges between the above listed factors