As time goes on and your relationship progresses past the courtship stage, you take on some pretty unfortunate roles: You are the aggressor and your partner is the pushover. Needless to say, this isn't the best way to foster a loving, mutually supportive relationship! Somehow, your lover's moods are too closely tied to your behavior.
If you're feeling active and aggressive, they take it personally, even if it has nothing to do with them -- and they shrink from the powerful energy you're putting out without even realizing it. That kind of cause-and-effect behavioral pattern can set up some tricky habits in your relationship, habits that are hard to break. Instead of giving in to this influence and letting it control your relationship, you might want to encourage this person to ask themselves, What's so scary about my lover acting angry or aggressive, or even just passionate? They might realize that there's really no real threat -- that it's just their buttons being pushed, and them responding just as they're programmed to: being the pushover, backing down in the face of a blustery display of energy. You have to learn to tone it down a bit and control those displays of emotion, while your partner has to learn to stand up for themselves. In the end, this could be a mutually beneficial learning experience -- with some real effort on both your parts, of course.