Why doesn't this happen to me

for when you no longer want children. it can be reversible, but not always. usually people in their 40's who are through with kids, and want constant unprotected sex with their lovers.

Do you still cum if you have a vasectomy?

You do, but think that all the sperm cells are dormant or dead in the jizz.

you do, as guest said, but it contains no semen, just seminal fluid. the semen is trapped from going further than the break in the vas deferens (the connections from the testicles to the urethra) they eventually die and are reabsorbed into the body. many people who have talked about such things have stated that it feels no different than before the procedure. now, there is a new alternative that should be available soon, if not already. there is a gel called "Vasalgel" that uses a gel that blocks the passageway of the sperm, but it is easily reversible. think of being in your teens and wanting to have sex, but not a kid. you could have it till you are 25 and ready for children. probably the best option since you don't have to worry about changing your mind and the reversal failing.