My family won't be coming home, so I'm staying over at my girlfriend's house today. I was excited to have sex until she got home, but then my girlfriend's older sister appeared in front of me! It seems that the trip plans were canceled at the last minute... Then, in a cute voice, she seduced me by saying, "I'm better at sex than you!" She even started playing with my nipples, which are my erogenous zones... Would I do it if my girlfriend's older sister, who is better in looks, style, and technique than my girlfriend, invited me? Or not?