Elementary school student 5th grader, 10 years old.

This girl is my little sister's best friend...
Turns out my stupid little sister told her friend she was going to show her what a grown man's penis looked like, so she brought her home. I obviously refused, but the girl didn't give up and came back to see me alone the next day to try to convince me. Even though she just wanted to see my penis at first, she eventually ended up asking me to have sex with her.

So there she was, lying on the bed, nervously clutching the pillow where her head was resting, legs fully spread. She was already soaked, so with the help of my hand, I lead my dick into her tiny hole and slowly began to penetrate her.
Before I could even enter, my penis suddenly slip out of her little vagina. Her 10-year-old pussy was so small that for a moment I thought it would be impossible for me to have sex with her, but I didn't give up, I couldn't possibly let down that poor girl that had put all her faith in me to be her SEX ED teacher, so I kept trying.
Eventually, I managed to find the sweet spot and I began to firmly dive my cock in. At that moment, the walls of her tiny pussy squeezed my cock so tightly that I had a hard time not to cum right there.