We've been dating for about 6 weeks but have been friends since childhood.
During sex I said "I love you". I actually meant it, I do love him. I've loved him as a friend for many years and now we're more. But TBH my saying that right then was mainly about me getting carried away in the moment than declaring undying devotion.
He murmured "me too" 
And now I'm wishing I could take those words back until they really meant something to both of us.
Or does it matter in the end who says it first or when?