HeliX doctrine:
Sexual behaviour of yours would be wasteful if it was not love-giving. For example, some men look at women's bodies randomly. This is not love-giving because the women don't feel men's love from it. Therefore, it's wasteful.
As another example, they touch their own sexual organ. Again, this is sexual behaviour, but it's not love-giving to the opposite sex.
Your sexuality belongs to women, and your sexual organ belongs to women, and therefore your sexual behaviour is to be only for the benefit of the opposite sex.
It's not enough that you're expressing love in your sexual behaviour. It must also be that it actually makes her feel good and that it serves her life.
Useless sexual behaviour would just dampen your aggressive drive, therefore reducing your ability to fight or exercise effectively.