My girlfriend and I have been dating for three months. Today is the first time I visited her house, and I heard that her older sister is also at home. I thought it would be a good idea to greet her sister nicely to make a good impression. When she came downstairs, I was almost shocked to see her J-cup breasts without a bra!!! She was only wearing a thin shirt, and I could almost see her nipples, completely unable to hide her seductiveness!!! I couldn't resist those large breasts, so unconsciously I approached and touched her. But she didn't get mad at me, instead she accepted me, allowing me to squeeze her big breasts, soothing my rock-hard cock, and even letting me have sex with her!!! I completely lost my sanity and crazily had sex with her despite my girlfriend being right next to us...