My girlfriend's sister is a girl who doesn't get excited unless she has a boyfriend. I don't know how or where she found out about my sex with my girlfriend, but she said, "Do you always have sex with your sister with a condom? Poor thing..." and said it was natural to have sex without a condom. She even whispered in my ear with a lewd look on her face, "If it were me, I'd let you do it raw!" When she said something like that, I got a super hard on! She finished me off by saying, "And it comes with a creampie!"