I, who was so bad at kissing that I couldn't even have sex with my girlfriend. Her sister, who knew about my situation, teased me by showing off her saliva-covered tongue and tempting me! "I'll teach you a real kiss," she said, and suddenly we were tongue-to-tongue! My whole body was licked sensually, and my penis was sucked until it was mushy! As our tongues intertwined and saliva was exchanged, my thoughts of my girlfriend and my rationality crumbled! I went crazy and even came inside her, and now I can't live without my sister-in-law's lips and saliva...