TIFU by thinking I was alone in the house

This actually happened about a year ago when I was 16. It was a school day but I was at home for some reason, I cant actually remember why, and the rest of my family had gone to work/school so I had the house to myself, but my dad did tell me at about midday a couple of plumbers were coming over to try and fix our water pressure and that they knew what to do so I could just ignore them which was fine by me. Come midday im lying on the couch scrolling on my phone when the plumbers arrive. And theyre actually mostly tinkering with the hot water box thingy outside, only occasionally coming in to test a tap or something, so its like they arent even there.

Now me, being a hormonal teen, all of a sudden get the urge to, yk, choke the chicken. And I enjoy doing it in big open spaces like my lounge room, it feels kinda freeing in a weird way. Plus I could hear the plumbers outside and the only way they would be able to see me is by looking through the front window, which they have no reason to do because they're out the back, or if they looked through the big glass back doors, which have very loud wooden steps leading up to them, giving me ample warning if one of them decided to come inside. So instead of retreating into the safety of my room I pick my poison and whip my shit out right then and there. Im about a minute deep when I hear footsteps, not from the wooden steps or the front window, but from inside the house. Ive never whipped my head up faster. I feel my heart sink to my stomach as I make direct eye contact with the plumber exiting my laundry room. I somehow didnt hear him at all for the 5 odd minutes he'd been in there and thought he was out tinkering with the box like the other guy. So I lock eyes with this poor plumber for like a full second, meat in hand, video blasting, and then all at once I turn off my phone and try subtly hiding my meat behind the pillows and he just turns and walks out the backdoor, which is right next to the laundry so he was gone quick.

I obviously stopped after that but I was to ashamed to even get up and go to my room so I sat in the exact same position until they left about 20 minutes later. After they left I went and stood where he had been standing to try and gauge how much he saw, and luckily because he was looking at me from over the back of the couch, I think the pillows mostly covered up my weiner, but he definitely heard the video, and he definitely saw the position my arm was in. I still lie awake at night and ponder why I did that dumb shit

TL;DR I masturbated in front of the plumber by accident because I thought he was outside