Your best friend wants to become sexually active. write a letter to him or her explaining the risks std's and hiv.

Hey i just want to let you know that it is okay to be sexually active just make sure you use protection. Stay away from random people and creeps make sure you know the person you want to do it with and don’t jump from person to person

Listen bro ive known u for a while now ur like a (brother/sister) to me and i want you to be safe because there are all types of sexual diseases out there and they can mess you up permanently and i dont want you to get messed up from someone that you wont be with for the rest of your life so i want you to get tested with the girl/boy before u get busy.. i want you safe so before you get freaky learn about what you might encounter 

BE SAFE 

Telling them to either contract or relax

No because males don’t have reproductive organs dummy