<human>: This happened last night/ this morning. 

Here is some background. I am a college kid (20)f living with my grandparents to save a shit ton of money.  I love them dearly, but they're very VERY old fashioned and have very strong southern Christian values.  Not a bad thing, but this makes the house rules very strict. 

So my boyfriend (21) is also student and works security jobs at night.  (He is a Marine, 6" and can be a pretty scary guy. Perfect for his job). But since he works nights, he has really shitty hours. So around 2am he's exhausted. And last night he happened to be working on a property  fairly close to my house. So I thought "what the heck, we can just sleep and maybe have some sex. No biggie." 

Turned out to be a big mistake.

The night went without a flaw. Took a hot shower in the morning. And we where cleaning up from the nights excitement when something rare happened. 
I heard a knock on my door. 
(Keep in mind, house rules state: you don't lock doors.)

With my door locked, my Marine stumbled and thumped across my room attempting to hide in my closet.  
I found myself trying to untangle myself form the sexy panties I was wearing the night before. And as I reach for the door, I find that it has already been unlocked by a spare key. 

I'm faced with my grandmother who just so happened to look over my shoulder to see my boyfriend attempt his dash for the closet, and myself in some very sexy stockings.... She turns ghost white.  

And I know I'm in trouble...

Can you give me the gist of the text in a nutshell?
<bot>: invited my boyfriend over to my house after a long day of work so BJs and sexy times, only to be caught by very strict and religious grandmother.