I didn’t respond and she started to knock the door very hard that I had to open the door in the middle of the act with a tent in my boxers and her b...a in my hands.Sister: What the hell were you doing?Brother (Me): You know what I was doing.Sister: But we decided to be strictly siblings and also, I have a boyfriend now.Brother: I am not asking you for sex, I am just shooting my cum in your clothes.Sister: But that’s so gross.Brother: No, it is not. I am sexually deprived. You think it is gross. Gary was lying on the floor between her legs and was busy introducing her to the pleasure of receiving oral sex, something Mandi had never experienced before. Her moans of pleasure indicated she was enthusiastically enjoying this new treat. To say this was a totally new and eye-opening experience for me, and for Mandi too, was the understatement of the decade.As long as Mandi was enjoying getting her pussy eaten (and maybe getting fucked) I decided there was no reason why I shouldn’t continue. Sometimes, she would have dropped her dirty ones on the floor and sometimes not. This day I had to make do with her pretty clean ones and I was a bit disappointed — but still excited as I took my pants off and softly rubbed the crutch of a pair of beautiful peach coloured scanties up and down my aching young cock — god, it was lovely — just like what I imagined fucking would be like. I was being very careful because I didn’t want to leave any trace of my doings. My cock was so big and stiff. Using both hands she pulled her outer labia apart and asked if I liked what I saw .She then said that she had taught my MIL everything she knew about pleasing a man and that she was the reason my MIL was so good in bed.. I rammed my dick in, started humping and pulling on her nipples wishing I had a rubber so I wouldn't have to contact her. I could not believe what a sloppy loose cunt this bitch had she must have really been a whore. I was pumping her so hard her saggy tits were flopping all.