Hi when I am watching porn videos after 2 or 3 hrs thr cum is coming automatically, Is it normal ?and when I do masturbate cum is releasing very early please suggest.

Question

Semen production goes on in the testis for 24 hours and gets stored in seminal vesicles. Now imagine seminal vesicles as a water tank. 24 hours production at some time, will make tank full. Its storage capacity runs out. Now overflowing mechanisms take place like night falls and seminal discharge in urine. To avoid this you need to have sex or masturbate regularly.
Now your tank is full, so slight sexual excitement will release sperm, and due to high pressure inside it, early ejaculation happens.

Vishal P Gor · Accepted Answer

Semen production goes on in the testis for 24 hours and gets stored in seminal vesicles. Now imagine seminal vesicles as a water tank. 24 hours production at some time, will make tank full. Its storage capacity runs out. Now overflowing mechanisms take place like night falls and seminal discharge in urine. To avoid this you need to have sex or masturbate regularly.
Now your tank is full, so slight sexual excitement will release sperm, and due to high pressure inside it, early ejaculation happens.