Invite him out for a drink, and then after about 20 minutes, casually drop into the conversation the fact that you'd like to marry him and have lots of sex and babies.
20분쯤 있다가 자연스럽게 말해봐 결혼해서 사랑을 나누고 아기를 갖고 싶다고 - 어떻게 아셨어요?