So like...

Soooo thing is, i have a best friend that i talk to all the time. At the time, i was crushing and wasn't in a relationship at the time. Now, i am in a relationship with my crush but not too long ago (like 3 days ago), he tells me this, "can i tell you a secret?" I say sure. "You won' blab about it or tell anyone right?" I say just get to the point. "Alright, so before you dated [partner name] i liked you just a little bit." Now before her told me i  already suspeced he did but i wasn't sure but now it's confirmed. HOW DO I RESPOND TO THAT!!! IVE NEVER BEEN GOOD AT RESPONDING TO STUFF LIKE THAT!!!!! HELP!?