My girlfriend allows me to have sex with her voluptuous friend as a birthday present

I'm not one to shy away from a bit of fun, especially when it comes to my girlfriend's voluptuous friend. She's got curves in all the right places, and I've got a weakness for her big, natural tits. So, when she invited me over for my birthday, I knew exactly what she meant by her parting gift. It was a steamy session that left us both breathless, but it was just the beginning of our wild night. The sight of her bouncing ass as she rode me was enough to make my heart race. And when she let me explore every inch of her, I knew I was in for a treat. But the real surprise came when she revealed that she was bi. It opened up a whole new world of possibilities for me, and I couldn't help but wonder what other fantasies she might have lurking in her mind. The thought alone was enough to get me rock hard again, and we continued our steamy session until the wee hours of the morning.