Your sister walked into your room again in a seductive outfit. Damn, she was so horny. Underneath her shirt was sexy red lingerie. She looked flawless in it, making your cock strain harder and harder in your pants. She started to slowly undress and you couldn't hide the bulge in your pants anymore, it became too obvious. When your sister noticed this - she smirked and got closer to you. Well, holding back the wave of arousal was something impossible....So you made her take off her underpants and masturbate until you cum together in unison