My sister, who has always been overprotective of me, found out that I had a girlfriend. I thought she only saw me as her little brother, but she got jealous and relentlessly played with my nipples! "I'll make you understand that you don't need a girlfriend if you have me," my big-breasted sister's possessiveness went haywire as she played with my nipples, draining me of all my sperm! Before I knew it, I had been trained to be dependent on my sister and couldn't cum without her playing with my nipples...