You are highly sensitive to this person emotionally, but not necessarily in a positive way. Instead of intuiting their moods and responding on a subtle, supportive level, you are more likely to overanalyze every signal you receive from your partner and end up misinterpreting their emotional cues. This can lead to trouble because you never have a fully accurate picture of how they're feeling at any given moment, and you might drive yourself crazy trying to figure it out.
If you have any emotional insecurities when it comes to love relationships, they'll be brought up by this one. If you're constantly trying to figure out what your lover is thinking, odds are you draw the more negative conclusions out of simple vulnerability. Furthermore, you two tend to have different tastes and interests, and you're also different on a purely emotional level. What you respond to emotionally leaves your partner cold. It's extremely important to feel loved in any relationship, but especially a romantic one, and that is hard for the two of you. For a long-term bond, you have to work at it, and be very conscious of what signals you're sending out and how they're being received. Similarly, you have to strive to love your partner in a way that satisfies them, rather than in the way that comes most naturally to you.