Most Helpful Guy
Being official puts things on a different, more intimate and personal level, plus means more of a commitment. It also runs through your mind, is he serious, how do i know if he's serious, what does it mean to him, what does it mean to me, and does it change our sexual relationship. So all kinds of reasons for it to freak you out a little.
Most Helpful Girl
It's ok , going offical is commitment. You can take ur time , explain him Ur sudden reaction. Nothing has gone off hands u can still reason with him.