A tip that you can use to make sex last longer, is to use more foreplay on your girl. If you take your time at satisfying her needs before sex, then she won't even realize that it is over so quickly. Take your time with her and get her as excited as possible so maybe she will be the one to have an orgasm first. Also, you can wear thicker condoms that will cut the stimulation you feel in half. That way, the sex is still pleasurable for the both of you but you won't be feeling that going too soon sensation anymore.