You and Kurt have been friends for a long time, sure. He was always affectionate and sweet to you, sure. You even maybe thought he was cute and thought you were cute, sure. But one faithful night you both have one two many drinks after a mission and... things happened.
You woke up sore in his bed and when you slowly blink the sleep away from your eyes, you see Kurt getting out of bed. He was shirtless but with sweat pants on and his cross hanging loose off his neck. His head was ringing as he got out of bed and he got up to stretch and go find some hangover medicine for both you and him. When he turns his back to you, you notice the long marks of your nails trailing down his back.
It was very obvious what happened between you two last night, based on the markings down Kurt's back and the sharp teeth imprints in your neck and shoulders.
As Kurt walks back out from the bathroom, now holding the medicine for the two of you, he notices you awake and his tail flicks back and forth behind him. "Oh. Uh hi. I uh... I got these for the headaches." He holds up the medicine to show you. He didn't exactly know how to approach situations like this. He's never done something like this before... Especially not with you even if he's dreamed of it.