Almost Caught Her In The Act

For any of you that may have watched a few of the video’s of my wife, you may have noticed that she is extra cautious recently... here’s why:
Earlier this year it was time to do the grocery shopping. Right now, this is one of the only chances she gets to be home alone for more than a few minutes. Knowing full well that she would likely take advantage of a bit of alone time, i had my camera rolling as i put on my coat and picked up the grocery list. She was busy taking down our xmas decorations secretly eager for me to get out of the way so she could get on with what she does best...
I grab the car keys and leave the house. Get in my car and put my phone on the dash ready to watch the action live on the way to the store. I put the key in the ignition, turn the key and my car made that dreaded ‘Click’ sound... Flat Battery.
Being just after xmas the house had been fully stocked and my car had been left stationary for almost a month out in the cold.
Wondering how i was going to solve my predicament I heard the familiar sound of footsteps from my phone as my wife was on her way to the bedroom to make the most of her alone time.
I watched as she stood next to the bed, undid the zipper on her jeans, lay down and reached for her bedside drawer...
As always, my heart started racing but this time was different. I was right outside under our bedroom window.
What was i going to do? Sit in my car and wait for the action to unfold? Or take advantage of this unique situation?
Phone in hand, i took the key out of the ignition and quietly made my way back in the house. Still watching her, panties round her ankles she was completely oblivious that I had made my way back inside. I could feel my heart pounding in my chest as i took my first step onto the stairs.
The 3rd step let out a loud creek from the floorboard... I’ve never seen my wife move so fast.
She simultaneously returned her Satisfyer to her drawer at the same time as pulling up her pants. Just as I got to the top of the stairs just outside our bedroom, she had just about managed to do up the button on her jeans.
I entered the bedroom and calmly explained the predicament about the flat battery on the car as she (in a slightly shakey voice) was telling me she had cold feet and had come upstairs to put on an extra pair of socks...
I had no intention of letting on that i knew what she was up to. I like to watch her masturbate and try very hard not to let on that I watch her in any way.
To this day she still believes she got away with it...
How i wish I had waited just a few more minutes to make my approach as theres no way she would have managed to hide it in time right at the point of climax...
Needless to say, she now checks that my car has gone before she proceeds to enjoy herself and any passing vehicle spooks her just in case it happens again.