I would take a deep breath, and go straight to it: dear ā¦(son, nephew, brother, cousin, etc), here are some of the consequences of pre-marital sex based on natural law and common sense, not even touching on the subject of how it is a grave violation of Godās divine law:
-broken hearts. should you end breaking up, both of you will likely have scarred yourselves for a lifetime and wonāt be able to stay on friendly terms with each other
-hasty commitments and hasty marriages, since itās not that easy to back off after you have been physically involved with someone, even if there are signs of serious incompatibility
-unwanted pregnancies and out of wedlock children (even if using contraception).
-a bitter taste of using someone and being used (feeling compounded if contraception is used)
-sexually transmitted diseases. Human papilloma virus and genital herpes are transmitted even if condoms are used. If his sexual partner had another partner within the last 5 years, he should be really concerned about picking up some nasty and difficult to treat virus stuff, even if she is apparently free of symptoms. Also, gonorrhea, chlamydia, candida, HIV-AIDS.
-a sense of failure and not living up to oneās own standards, even if āeverybody else is doing itā
Good luck. If he stayed chaste, it is still not wasted time to have a frank discussion of the dangers out there. Peer pressure on young men can be horrible, and itās not easy at all to go against the prevailing secular culture.