Especially if other factors support a fast, warm bond between you, this one could make both of you feel as if you were meant to find each other and fall in love. After all, you loved each other in a past life, and slipping right back into those feelings, as well as those roles, will feel as natural as anything. But stepping backward into the past isn't necessarily the best course of action, no matter how comfortable and familiar you might feel to each other -- and especially not for your partner.
They need to grow, to evolve and progress, not to step backward in time to relive a love long gone. They may even sense that the old love affair you shared was never finished, and that there's unresolved business between you in this life. But even if that is true -- if your past-life relationship ended painfully, or just prematurely -- what's the point of resolving the karma now? If you stay together as a couple, your partner will have a much harder time of moving forward toward their future. Involvement with you in this lifetime will mean they've slowed down on their path of personal evolution. Are you sure you want to be responsible for that?