Take it slowly and don't rush it.
It all depends on how you condition your body. If you have sex every day for a month and then not for a week, your body will be expecting it and not be getting anything so you will become sexually frustrated. If you go without sex for a long time, such as several years, your body will not care about it as it is no longer a part of your life.
All their lives
Sex can last a period of time depending on the two sex mate
anything over 3 days HA HA
by the age of 18
You can't, best to get a few condoms.
Yes, it may decrease the sex drive.
Some people have gone their whole lives.
Men certainly CAN live without sex. But most would quite prefer to live WITH sex, as long as it's possible. Not many people - men or women - would deliberately choose to live without something that they really enjoy.
Why not go for as long as you are single, that's what being single is for, right? Enjoy it while still young and single.
A vasectomy ============== I am not sure what the questioner realy wants to know (perhaps a medicine to delay a man's ejaculation so as to make the sex act last a longer time?). However, the "vasectomy" answer does not seem relevant. Vasectomy is a surgical procedure that blocks the path of sperm, allowing the remaining fluid of semen to be ejaculated normally. It allows a couple not wanting children to stop using condoms or birth control pills. If it prolongs the act of intercourse for some individuals, that is probably a byproduct of relaxing, without the fear of accidental pregnancy.
You don't always get pregnant after having sex that first time and it doesn't happen when you want it. if you've had Chlamydia for a long period of time before you got the medicine the Chlamydia can also have made you sterile. Sadly, that is one of the side effects. And you two should not have unprotected sex while undergoing treatment.