<human>: I've been lurking on r/tifu for quite some time, and finally have something embarrassing enough to contribute! Though the FU happened today, it needs a bit of back-story.

I went to watch 50 Shades of Grey with one of my best girlfriends over the long weekend (it's really more funny than arousing) and while waiting for popcorn, I happened to see my very Greek Orthodox physics teacher. I waved and prayed to the gods that he wasn't expanding his interests to BDSM. Thankfully, he wasn't and I forgot about the whole situation. 

Unfortunately, he seemed to have remembered. Today in class, I asked him a question and while I'm writing down the answer, he asks me, "so what movie did you see?" 

"UMMMMMMMMM" 

My heart and mind raced as I tried to think of ANY other movies playing in theaters right now, but, my brain couldn't do it fast enough and with my head in my hands, I confessed, "...50 Shades of Grey". 

"Oh". 

I couldn't stop nervously giggling as I asked him what he watched. He mumbled something about Kingsmen and how there was some risqué scenes in there as well. I awkwardly nodded and said "I'll just leave now" to which he said, "yeah...good idea". 

We didn't make eye contact for the rest of class.

Could you distill the essence of the text into 1-3 sentences?
<bot>: My physics teacher's image of me as a sweet, innocent student was shattered when I told him about the raunchy movie I watched.