Sex b4 marriage is a sin. But if your gonna marry the guy then its not. Why do you think so many girls once they've slept with a guy they pressure them to get married? If you marry the guy its not. I kno SO many girls that hav dun that!
itz a sin i think even if u marry that guy afterwards...aap ne us time tou apnay nafs ko kaabu mai nahi rakha na wen u were supposed to..us time ka gunnah tou likha gya..baad mai shaadi ker lena puraana gunnah khatam ker de ga kya??lLogically if u think,itz a sin..