To be honest this is a difficult question to answer, because it's difficult for me to put myself in this situation to begin with.
But let's play "What ifs". If I did find myself in this situation, I'd definitely be uncomfortable with it. If I was that far in a relationship with someone where our connection was that solid, then the next logical step to take would be to start moving towards marriage with that person. But that requires more than just love, physical attraction, or "feelings", as trust and dedication to one another are necessary as well. So despite my understanding with her hesitation to tell me this secret, it'd still hurt me that she kept this from me all this time.
However, despite all that, there's an obvious connection that cannot be ignored. I hate to sound cliche, but even though my body and mind are hurt and confused in this situation, there's still a heart connection between us, so it'd be foolish to let this situation completely sever that. It's certainly something to think about, that's for sure.
She also gets bonus points for Sonic cosplay. All I'm saying is that it wouldn't hurt.