I would say that if you are counting the lock in that picture as a copulation, I would say not. Their cloacas are too far apart for that to be a lock in my mind, however, it may just be the angle of the picture. I don't really know of any tricks, but do know that some of my pairings have locked up, and then when reintroduced, they will not. Then low and behold a month later they will lock up again. This is one of the more frustrating parts of breeding. Sometimes they will, and sometimes they won't. Also, I find that they ones that really drive us crazy, are the ones we are wanting to breed the most. It just happens that way sometimes. Good luck on that pairing, and I hope you get a Lavender.