Hi well come to HCM.
Thanks all this phenomena are normal need not worry semen can come if lot of
collection due to lack of masturbation
even on little excitation which might have
occured during sleep which you might not have rememberd.In erection always penis
becomes of full size and asper the age advancement hormonal
changes are bound to
occur.No need to avoid masturbation and donot keep tension of all this. Thnks