What's My Step Brother's Cock Size?. "Everything began to make sense after I saw a picture of my cock on my stepsister's phone.. As she attempted to explain the dick pic, she grew more embarrassed. It was too cute honestly, and impossbile to be mad at her! Apparently her friends had put her up to it. But I think she seemed to enjoy her big stepbrother's cock... Earlier in the day, I peered into her room after hearing her passionate moans.. And I noticed...