Hi iamjohnlee,
Welcome to HCM Forum ,
After age of 10 - 12 , many
hormonal , physical and mental changes happens in body. Development of sex organ is one of them.This is age when semen starts forming so that till now you might have seen that previously it not use to came out and now since few years coming out.
Like urine and stool, semen also regularly formed in our body.In similar ways when it formed to certain quantity it develops desire to urinate ,defecate similarly develops desire to masturbate also.Semen like urine and stool not of much important to body hence forced out of body by appropriate function (either by
masturbation consciously or unconsciously by nightfall, urine by urination,stool by defecation etc.)
It has been taught since childhood about other things (You should regularly go for urination, defecation) but not discussed about masturbation so we are always confused and produces guilt that why this happening to me.
So Desire of masturbation is natural process to expel semen (which not much important for body) in similar ways as body functions regarding other things in body which not of much importance i.e.urine,stool etc and hence its natural and " 100 % normal "
As semen doesn't have any importance (except for increasing progeny by fertilizing female egg) it does not produces any side effect by expelling it on body or not will reduce your height.
In fact Doing masturbation gently will help you by...
1) give outlet to your natural sexual urge and avoid distraction in your routine
2) helping to empty semen reservoir so to avoid nightfall
I hope this will answers your query.
Best regards.