After the darkroom

It had been 2 weeks since the party where my sister had unknowingly sucked me off.
The days that followed the party, Sara seemed to be almost flirtatious with me.
I was sure she knew it was me in the darkroom.
I would catch her walking around in her night shirt or bikini.
She would have a little extra sway in her hips as she passed by, as if to say “Look at my ass.”
I swear she would find things to suck on in front of me jus to tease me with that big smile across her face.
Still she didn’t mention anything about it directly.
As the days passed her flirtation seemed to wane. I still jacked off multiple times thinking about that night and her swallowing my cum.
Then, one weekend my mother decided to hire me out to help the neighbors get ready to move.
I spent most of the day helping them pack, cleaning and painting. When I got home I was beat. Still mom seemed to have a lot more things for me to do before my day ended. When it did end, I didn’t even have the strength to masturbate. I would take a quick shower and fall on my bed. I repeated this episode on that Sunday as well.
When I woke up Monday, not only was I happy to have nothing to do, but I had my friendly morning erection staring at me.
I reached down and started to stroke it when I heard my mom calling me.
“In a minute” I yelled back. I only needed a few minutes to take care of business.
Mom wasn’t in the mood to wait and told me to get downstairs pronto!
Somewhat frustrated I got out of bed and pulled on a pair of short and a t-shirt and headed down.
Luckily my erection was partially deflated by the time I got to the kitchen.
My sister was already there and gave me a quick smile as I came in. I noticed her sitting at the counter in her usual sleep shirt, though her hair was a little wet from her shower earlier.
Mom was standing by the counter putting some food in a bag.
“What’s up” I asked?
Mom told us that she needed to take some food over to the Karzies, since Ms. Karzie had just gotten home from having surgery.
She wanted to let us know that she would be gone for the next 4 to 5 hours and wanted the house cleaned while she was gone.
We both agreed we could have it done, seeing how it only took about an hour for us to normally clean it.
I told her I could start after I took a shower. After that she gave us each a kiss on the forehead and walked out to her car.
“I’m gonna go hop in the shower” I told Sara.
“Sure thing bro” she replied and walked over to the fridge.
I walked up stairs and went in to the bathroom to take my shower.
As I got in, the water was warm and I washed my hair. Then I thought about finishing what I wanted to do when I woke up.
I slowly started to stroke my cock, feeling it beginning to harden when my sister came in the bathroom.
“Got any more clothes in here” she asked? “I’m going to start the laundry.”
“Just what’s on the floor” I responded, taken a little off guard.
Sara grabbed my clothes and walked out.
I took a minute to recompose myself and stated back on the mission at hand.