Here’s what I think, your friends shouldn’t interfere with what you want to do. They can’t choose what you are ready to do because in the end the only one left for yourself is you. If you want to have sex and are ready to  be responsible, then go for it. Just remember there are only two people in a relationship, it should only stay in your relationship. Your friends don’t really have a right to know what goes in and out of your relationship. If they judge you for your descion, they shouldn’t be classified as your friends. Maybe they just suggested that because they want the best for you. But if you feel you are ready, you are ready. Hope that helped you :)