Recently, it seems my sister has gotten a boyfriend... I became her practice tool for fellatio because I wanted to be praised by her boyfriend. She said, 'Even though we're siblings, it's okay just for fellatio, right!' and started practicing fellatio on me. 'Hey, big brother! One more time!!!' After ejaculating, she continued to suck without taking a break, making me cum repeatedly while still having semen in her mouth. I was thoroughly manipulated and kept going until my dick became stupid. Much more seriously than expected, my sister was... really into it.
