I fucked my best friend [M/F]

A couple of years ago, I moved away from my home town to go to university. The university I was attending was about 6 hours away from my home town so I didn’t go back often, however one of my close guy mates was having his 21st birthday, so it was an important reason to go back. My parents had moved away after I finished school and moved so I had to check into a Motel to stay the weekend. I asked one of my best friends, let’s call her Mia, to pick me up from the airport. Mia and I have had a close friendship, but has never been sexual. Mia is a fox, about 5’ 6” with brunette hair, blue eyes, slim figure and C cup tits. I myself am about 6’ 3”, brunette hair with brown eyes and reasonably built.
Anyways, I flew in to my hometown, and Mia was there waiting. She ran up, gave me a hug and done the whole “omg how are you? You look well, tell me what you’ve been up to” so I got my bags and we had filled each other in on what had been going on in our lives. Long story short we made it to the motel I was staying at and I checked in to my room.