My Lesbian Sister

I got for the first time ever, a girl knocked up. My sister is 28 and her wife, Mary is 25, and super hot as is my sister. My sis said they wanted a baby, and instead of paying all the money to do any of the normal procedures asked if I would agree to father the baby. No more responsibility except that I would have as an uncle. I thought at first they wanted me as a sperm donor, but my kinky sister, who used to set me up with her friends and their sisters in high school, said she wanted me to fuck her wife. They knew the cycle, and to be "safe" they blocked out a 6 day period where I stayed with them, and fucked her whenever I felt like it and she would then push pillows under her, lift her legs so the sperm rested right on her cervix. Turns out, unbeknownst to me, though Mary didn't have her hymen in tact, my sis had taken care of that about 8 years earlier with one of her dildoes, Mary was a virgin to male-female sex. She'd never had a cock, never had sperm inside her. My sis was there the whole time, even helped suck me to get me hard as Mary had no idea how to suck a cock decently.

I got her knocked up, and I still get to fuck her every once in a while. My sister loves to watch me fuck her pregnant wife, and I like fucking a preggo bellied woman it seems.