My step sister teased my unmercifully when we were growing up. She would flash me naked, but I wouldn't f*ck her because she was underage. When she turned 18, I popped her cherry. We now f*ck every chance we get when we are alone. I wonder how many other guys are s******* their step sisters, legal or underage? It's a temptation hard to resist when you are both living under the same roof.