The male's penis gets hard naturally when you are in the mood because your body is urging to have sex. The penis and the vagina fits like a puzzle. When the penis gets hard it also gets bigger and is easier to penetrate and gives more pleasure to the girl
Penis get harder only if you feel some sexual appeal.
The hardness is due to the blood circulation in the penis as the penis has no bone it just made from the flesh.
The hardness is due to the blood circulation in the penis as the penis has no bone it just made from the flesh.
Puberty. ;). When your penis gets hard, you have, a boner, or an erection. An erection happens when your penis gets sexually excited. Sounds weird, but your penis has a mind of its own. :/