A few days later, I heard mother leave and opened my bedroom door as usual. Yet, this time I thought I'd watch to see if Sally was going to do a naked dash for the bathroom as she did earlier in the week. I peeked through the crack between the jamb and the door as I heard Sally giggle and run the gauntlet of the landing to the bathroom in the raw.
I saw her plump little ass again as she ran away giggling and I laughed to myself. The little minks, I thought, if she's going to go streaking naked on the landing then so am I. I'd have more in store for her though. When she was in the bathroom, I sneaked out and locked her bedroom door, so when she returned naked, she'd be trapped on the landing.
I planned to wait for her to finish her ablutions and then run out naked and flash her as she stood trying to get into her bedroom. I waited as she merrily sang to herself as she went about her business until eventually, I heard the bathroom door open.
I waited behind my bedroom door, straining to hear the patter of her feet and then trying her bedroom door before I would run out and join her myself.
I looked down and saw I was very erect, most likely through morning glory, although the thought of my little jape could have been the reason. What the hell! She'd seen my cock a few mornings ago anyway so hopefully she wouldn't be too shocked.
The timing was everything, I'd wait until she's trying her door and just as she realised she was locked out I'd jump out naked and block her retreat to the bathroom.
I strained to hear with my ear to the door in the still silence smiling to myself at the thought of my ensnared sister, panicking nude on the landing. I listened to her quick shuffling feet over the carpet and then the turn of the handle of her locked door.
I jumped out and landed with my legs spread facing her bedroom.
"Ole!" I shouted with my arms held high only to see nothing before me but Sally's closed door. I quickly turned around. A scream rang out behind me as I saw my sister naked, desperately trying to cover up, staring in horror at my boner pointing up at her.
"Oops! Sorry!" I cried, putting my hand over my erection.
"Out of the way!" She yelled and tried to push by me to my right. It was the same side I sidestepped to. She bounced off my chest hard enough to make her little boobs judder.
"Out of the way!" She frantically cried.
I moved to the left as did she and once again our naked bodies collided but this time her hand smashed me hard in my balls.
The sickening impact zapped through my body, and both my hands quickly held my throbbing testicles as I dropped to my knees. I tried to be sick as I gathered up in an agonising ball in front of her.
"Oh sorry," cried Sally as she urgently tried to straddle over my prone body and reach for her bedroom door handle.
I rocked on the floor wanting to die as the sickness of my testicular throbbing focused my mind with tunnel vision.
I faintly heard Sally's failing anxious attempts to open her door.
"You've locked my door, you bastard, give me the key, give me the key!" She cried in panic, rattling the door handle against logic.
"What's going on here!" loudly demanded a voice authority from the other side of the landing.
It was our Mother, and I tried to push to my feet despite my searing testicular pain, and in doing so, I lifted Sis in-between her legs.
She screamed again as her legs were parted by my rising back, causing me to overbalance and make us both fall to the floor naked. Mother was soon standing over us as we untangled our nude bodies.
"What are you doing?" Mother bellowed in outrage.
"I can explain," I grunted against the entire ache holding my balls along with my dwindling erection.
"I've been locked out!" Pleaded Sis covering her tits and pussy.
I was cripplingly sick, almost paralysed with my testicular pain, causing a ferocious cramp in my stomach. The pain and humiliation were earth-shatteringly vicious, severing my ability to think and argue. I regressed to the actions of an animal.
I crawled away to the safety of my bedroom, as Mother and Sally argued in an audio blur. I got inside my bedroom door and blacked out. Sally was left naked, stranded outside her room to face the searing wrath of our lunatic Mother.
Later we were both sat at the breakfast table as Mother severely reprimanded us. I owned up as it was my fault and tried to explain, but Mother was deaf to my explanation.
"I've been suspicious of you two getting up to dirty things for months, so what's going on?" Sternly demanded Mother.
"It was supposed to be a Joke," I pleaded.
"With both of you naked?" snapped Mother.
"It went very wrong, I just wanted to trap her on the landing by locking her out."
"So why was she naked and why were you erect?"
There was no explaining that away, not innocently, and I bowed my head in shame.
"I come back home to find my children wrestling on the landing naked! What else has been going on? Do I need to contact your father?"
"No! Look, it was just a practical joke that went wrong," I pleaded.
"And what have you got to say for yourself, young Lady?"
Mother hissed turning on Sally.
"I was locked out of my bedroom."
"So why were you naked? It's not like you've anything to show off anyhow!" She cruelly added, causing Sally to burst into tears and runoff.
"Pathetic!" mother shouted after her, "The pair of you, both nearly nineteen and neither of you courting!" She added really going for the bone. She ran to the foot of the stairs and shouted after Sally, "No one will have you, so you start fiddling with each other, well not in my house!"
In her bedroom Sally hurriedly moved from cupboard to chest to drawers, clumsily extracting fistfuls of clothes and bric-a-brac to stuff into her rashly opened suitcase.
"What are you doing?" I asked in denial of the obvious as I tried to collect my real thoughts.
"I'm going!"
"No, don't go!" I cried suddenly realising the frightful horror of how much I depended on her. She was my sounding board, my crutch, my only connection to real people in the outside world. The thought of her leaving hit me hard, as she was in truth, my only friend.
I apologised repeatedly and pleaded with her to stay for my own sanity more than anything else. I started to piece together the implications the loss of my sister would mean. It was a flashpoint; a fracture in which I knew if it was played out to the end the damage would be irrevocable.
"She has a point," remarked Sally, an unjustifiable reason to me but rationally presented by my sister causing bafflement on my part. "It doesn't look good, not after father watched me in," Her voice trailed away.
"Watched you, watched you doing what?"
Sally cut me a Siam stare as she went about her packing.