I took my boyfriend to my best friend's house to check on his cheating habits, and sure enough, he started having sex with my best friend while I was away. So I decided to seduce my best friend's boyfriend, and showed him my panties to get him in the mood, and then I took his big penis in my mouth in the bathroom. My boyfriend and best friend saw us, and we swapped! I had sex with my best friend's boyfriend in front of my best friend and her boyfriend! This was my first time swapping couples, but I didn't know it could be so exciting.