How sex harms men?

1. Sex drains a man because it's mainly a man who performs physical strain during the act of sex. Increased oxygen consumption by all body parts rapidly depletes body energy levels.

2. Sex enhances attraction towards the opposite gender, thus increasing the craving for her. The lust increases which is normal but sometimes this gets out of his own control and that's when others get a chance to criticize by calling him maniac even though they themselves enjoyed it during their youth. 

3. The female gets an easy chance to bargain for anything in return for allowing sex. History shows use of vish-kanya by Acharya Chanakya. Honey-traps are very common mechanisms used by terrorist groups which succeed even when most others fail. 

4. A man in a sexual relationship becomes highly vulnerable to false accusations of sexual violence.