Hello all!

I'm currently attempting to determine the sex of my adult ball python "Oliver". He is a rescue that I have had for around three years and just never worried about sexing him. I recently got a probing kit and thought "Hey, why not?". He is 2100+g and was an adult when I received him in 2010. His previous owner believed that he was a male and around five at the time though when she got him he was also an adult. Anyway, below is the picture of how far the probe went. Just kinda curious to see if Oliver is male, thank you for any help! :-)