Even if you're normally a very placid and understanding person, this relationship will gradually work up your inner aggression over time, until your temper either implodes or boils over -- or until you address the karmic ties you have with this person, whichever comes first. In another lifetime you two were connected, and whether your bond was romantic or platonic, one of you deceived or betrayed the other, creating an atmosphere of suspicion and distrust that has carried through to the present day. Your partner's penchant for secrecy will get under your skin in ways you may not be able to imagine until you experience them.
It's hard to say who will bear the blame for these issues; on the one hand, your partner will be rather secretive with you, keeping you in the dark regarding their true feelings and agenda. But you may do the same thing to them when you passive-aggressively hold in your annoyance at them while letting them know in other, less direct ways that you're upset. But instead of repeating these same, tired behaviors, you would both be better served by making a commitment to gentle honesty from the very beginning. Passive-aggressiveness is out, as is outright aggression. Instead, take the kind but straightforward approach: Speak your mind and ask your partner to do the same. If they simply can't bring themselves to be honest with you, then perhaps you'll have to rethink whether this is a relationship you really want to pursue.