Girlfriend's Sister

I am addicted to the thought of f****** my girlfriends sister. She is hot 1 65 with curly hair. Nice tight fit ass and silicone C cup t*** with big hard nipples.She has a bitchy style but she is not like that. She has a family and she is not looking be in a mood of cheating. I cant stop thinking and masturbating on her photos. I want to f*** her and c** in her p****. Rub her t*** and slap her ass.Please help me