肢体语言要合适。 说你爱他。 等他的回答。 恰当地做出反应。

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in English about that?
Your body and face should tell your boyfriend how you're feeling before you say a word. You can already let him know that something is about to happen with the right look and the right gesture. Here are a few things you can do:  Maintain eye contact. You should stare him in the eyes without being too intense. Make him feel important. Turn your entire body toward him. Let him know that he has your undivided attention. Touch him lightly. Put your hand on his knee, graze his shoulder, or rub his ba