Fin things in common with them. It's really easy! Just interests, movies, books, activities, ect. Whenever you feel that you are losing the person, revolve around interests. And in intercourse, the be able to ejaculate/ achieve orgasm, think of the same sex. Have the sex, but think of the same sex. You will still ejaculate, only over something other than your partner. And the best part is, they would never know!