im not sure if this works for bp's but it does for scrubs, take away the hot spot so the entire enclosure is one temperature, hot spots are known to completly distract males while females stay at the cold end, therefore they never breed. other than that maybe just wait it out? if snakes dont want to breed, they wont, and if they do, they will, so i imagine that more time is your best bet.
that or you can duct-tape their cloaca's together lol, they'll figure it out eventually, right?