Caught Masturbating

So I was sleeping up in my room in my boxer briefs like I normally do. I got to sleep in because my mom and older sister were going to church and I didn't have to go. My mom came into my room before she left to grab my dirty clothes. She asked me if the pile of clothes by the door was the only needed to be washed. I said no because my boxer briefs were dirty too, but didn't know if she wanted them. She asked me to take them off because she was going to throw a load into the wash before she left. I was a little shocked when she asked, but then she was like I won't look or anything just stay in bed and get dressed once we leave I was like ok kinda weird.

But I did what she asked and slowly slid my briefs off and tossed them over to her. I told her I loved her and she left. I ended up falling back asleep once she left. I woke up like 35 mins later with a huge boner. The sheets were poking straight up into the air. I couldnt help but start to stroke my shaft, I reached under my bed and grabbed some dirty panties that I had taken from a mom that I babysat for the other night. I spit into my hand and rub it all over my cock and start rubbing faster. I rubbed for like 10 mins on and off while smelling the dirty panties. I start to cum all over my stomach, legs, and balls when all of a sudden the door slowly opens and my mom pokes her head in asking if I'm up yet. She just stares at me in shock. I'm totally still just looking at her I can't cover up because I'm covered in cum. I didn't know what to say, the first thing she says to me is o boy I'm sorry hunny and then closes the door. She ended up giving me the sex talk later night once my sister left later that night. It was so embarrassing, but she said she was ok with it and not to let this incident stop me from playing just that I need to be more careful.