Im man,20. i masturbate 3-4 times a day. for each time im ejaculating quickly then the before one. why is it happening? and why im feeling horny right after masturbation again?

You have to much anxiety and tension at your age. Either find a girl friend or a sport to release your frustrations. Find a pet or go fishing or play soccer or cricket.

There is not much left after you masturbate the second and third time. Horny-ness is a mental state and very subjective. you have to figure it out. Too much of a good thing is not necessarily a good thing. May be you can find time for other outlets like social service, painting hiking etc. Good luck.