text: why did my boyfriend cum so fast when we were having sex? my boyfriend and i don't have a very exciting sex life and don't engage in the act all the time, the other day when we were having sex it lasted not even 4 minz and was done. thatz not usally like him. whatz up?? premature ejaculation.  if it is not used alot he may become stimulated too fast.  if he would like to prolong the use of his love pole, he needs to use it more and practice long stimulation.  premature ejaculation, also known as rapid ejaculation, or by the latin term ejaculatio praecox, is the most common sexual problem in men, characterized by a lack of voluntary control over ejaculation. masters and johnson stated that a man suffers from premature ejaculation if he ejaculates before his partner achieves orgasm in more than fifty percent of his sexual encounters. other sex researchers have defined premature ejaculation as occurring if the man ejaculates within two minutes of penetration; however, a survey by alfred kinsey in the 1950s demonstrated that three quarters of men ejaculated within two minutes of penetration in over half of their sexual encounters. today, most sex therapists understand premature ejaculation as occurring when a lack of ejaculatory control interferes with sexual or emotional well-being in one or both partners. an estimated thirty percent of men suffer from premature ejaculation on a consistent basis.