Me and my friend

My friends caught me wanking when we rented a apartments and it was an embarrassing moment cuz I just cummed and he walked in and stare at me and kinda smiled he then start speaking to me about it few week went by and I was at his house just chilling then out the blue he said I want to have a wank with u so it happen but nothing more then few days later he asked me if me and him can trade pic of are older sister and wank over then I was like okay and for a joke I did ask can u give me 1 of your sister thong to cum on and he went and got it for me a purple panties funny bit is his sister wear them without knowing I cummed on them but now we also wank each other off