<human>: Can you provide a brief rundown of the text in within 3 sentences?

Like most of the TIFU stories this didn't happen today, but rather 5 years ago when I was about 12 years old. My brother (we'll call him Mike) and I were in my room late at night, bored when he showed me his new laser pointer he'd just bought.  

After minutes of messing around with the laser, my 12 year old mind thought it would be a funny idea to shine the laser up my brother's ass to see his lit up anal cavity. Keep in mind we were just weird little 12 year olds when this happened (so we didn't think it was all that odd).

After a few minutes of exploring the depths of my brothers butthole, we both thought it would be even funnier to poke a hole through a water bottle and pour water up his butt and then shine the laser to see what that looked like...We did this and Mike muttered the words "I don't feel good" because honestly who would feel good with water poured up their butt? 

What happened next was a moment of my childhood that I'll never forget and is still one of the most embarrassing moments of my life. My dad opened the door to see the sight of me shining a laser in my brothers butt. This must have been nerve-racking for my brother, because he tensed up and shot poop water directly in my face as my poor dad witnessed the entire scene. My dad immediately closed the door once he saw this and he hasn't spoken a word of it since.
<bot>: Shined laser and poured water in brother's butthole, dad walked in, frightened brother spewed his butt juice on my face.