Masturbation quickly can ejaculate, but sex when ejaculation is relatively slow, mostly related to the following situations: 1, masturbation stimulation is greater than sexual intercourse: masturbation stimulation intensity is higher than sexual intercourse, and most people in masturbation is to quickly reach orgasm ejaculation, will be under the dual influence of psychological suggestion and physiological, speed up ejaculation; 2, the existence of guilt about normal sex life: this is a psychological reason, some people on Sexual life inner subconscious there is a sense of guilt or fear, so it may also lead to sexual dysfunction, slow ejaculation; 3, partner factors: such as men and women in sexual life, the female fear of pain or fear of pregnancy, as well as the male sexual organ stimulation is not enough, will also lead to slower ejaculation when men have sex.