I've been doing this for about two years, and I haven't yet been caught.
It's 2AM. Everyone at home is sound asleep. Well, almost everyone. Awake and horny, I quietly walk towards the living room, by far the most public place in the house. Anyone walking downstairs or from either side of the house would definitely see me. Regardless, I make my way into it and sit on the couch against the far wall.
I undo the button on my pants and slip my right hand inside. Through my underwear, I lift my penis and slowly begin to play with it. The thought of getting caught gives me goosebumps. After a few minutes, I get off the couch and onto the carpet floor.
I nervously take my shirt off and toss it aside. I do the same with my pants. Once again, I slip my hand inside. This time, I do so within my underwear, and begin to stroke my penis. With my other hand, I slowly pull my underwear off.
Once I'm lying completely naked on the living room floor, I begin to stroke my erect, five inch, rock-hard penis a lot harder. After a while, the tip begins to moisten. I switch hands, and with my right hand, I wipe the cum off and put it in my mouth. I continue to do this for a few minutes, gradually increasing in speed.
Once I reach the climax, I slow down, let go of my hand and watch as loads of warm semen fly across the room. I wipe the remains and savor them in my mouth. Once I'm done, I get up, but before heading back to my room, I put my underwear back on and walk around the house, frequently slipping them down and stroking my penis.