Be careful of mixed signals in this relationship -- your partner runs the risk of misinterpreting you on an emotional level, or missing your signals altogether. It isn't for a lack of interest; they are almost too tuned in to what you're thinking and feeling. But they're highly impressionable when they're around you, which is a difficult influence to handle.
They pick up on your emotional currents, and odds are, they misinterpret them -- and then run with whatever they've come up with. If they tend toward insecurity in a romantic relationship, this could spell disaster! For example, they might end up frequently thinking you're upset with them, when really you're just low-energy or preoccupied with something that has nothing to do with them. Then you pick up on your partner's hurt feelings and think they're mad at you, but you don't know why, and so on. The key is to talk things out, honestly, clearly and gently. Since your mutual tendency is to interpret and react without actually checking with each other to make sure you've interpreted correctly, you both have to retrain yourselves not to react so quickly. The probability is high that you both operate based on past experiences -- what the emotional climate was like in your house growing up, for example, or in your previous love relationship. You have to work hard to move out of the past and into the present of your relationship.