Hey, I just saw this thread.
You can "pop" him. You can press your thumbs down near the vent forcing the hemi-penes to pop out. If done correctly, this will not hurt your snake and he probably won't even know you're doing it. If he is producing sperm, you will know, because that too will come out. DO NOT ATTEMPT THIS is you don't know how and there is no one near that can show you.
How much does he weigh? Are you sure he is a male? Have him probed if you are not positive. I have 2 males now that are both only 350-400 grams each producing sperm and spem plugs!! It really depends on their weight more so than age...
