Okay, here it is. Foolproof. Only Nekosama could fuck this up.

You wait for your pubes to grow out to about an inch long each. You should have a decent bush by then.

At this point, you just take a lighter and *fwoosh*. Get some lotion, rub it all over (masturbate if you want to) and youre good to go. The pain from the burns will also heighten the excitement of sex.
And its cool, because by the time it heals, it will be time to go at it again.