Inexperience.

Next time you see an SP, tell them your problem. Let the pro do all the work, just relax.
 
If you are jacking off everyday or very often it can make it so you can’t cum atleast from my experience with guys. One of my regulars could never cum… I told him to go 14+ days without cumming or jacking off. He came within 10 mins 😂
I gotta so what hes doing I'm the reverse wtf