Surprising discovery: My girlfriend and her friend engaging in sexual activity, and they invite me to participate!

I stumbled upon my girlfriend getting down and dirty with her friend, and to my surprise, they invited me to join in. What started as a steamy threesome quickly escalated into a wild encounter, with my girlfriend\'s friend showing no hesitation in taking me on. It was a sight to behold as they explored each other\'s bodies, leaving nothing to the imagination.