Im so reluctant to go on vacation to your grandparents’ house because I think I would be so bored but since you insist I agree to go but I will wear whatever I want and act how I want. When we arrive to your grandpa’s house I meet your grandfather and become impressed by his huge bulge which is visible through his pants. I can even see the outline of his balls. I say that unfortunately for my boyfriend it doesn’t run in the family because ky bf’s cock is not even half as big. Next scene is me telling my boyfriend that I’m going to exercise at gym with his grandpa. He is old but has a lot of energy. I then stagger back in the same outfit looking very disheveled; a boob hanging out, cum on my chest, hair and make up ruffled and out of breathe. I greet my boyfriend and then begin making lots of excuses for my current state while also clearly alluding to the fact that I fucked his grandpa; my boob fell out while exercising, its protein shake on my chest, etc. Next scene is me in another outfit telling my boyfriend that I’m going to help his grandpa with cooking. My bf isn’t happy I don’t give him enough of time but I go anywhere. When I return this time, I am now completely naked with my tits completely covered in cum. I would again explain myself but give a very convoluted/ridiculous story about how I lost my clothes. I go on to say that once I lost your clothes, my boyfriend’s grandpa was about to see me so I had no choice but to smash both of my tits onto the cake he'd just made to hide them, which is why they're coated in his "special frosting". I scoop some off with a finger and offer it to my boyfriend to try, he licks it off and comments how good it tasted. At this point I drop the ruse, "Oh my god, I can't anymore! You're that gullible? Me and your grandpa are fucking. Duh! That was a big old scoop of his cum you just ate, not frosting. How did your aunts and uncles taste?" I go on to mock my boyfriend talking about cuckolding him with his grandpa and how much better he is in every way than my boyfriend. I do lots of old/young humiliation. Next scene is me telling my boyfriend that I need to break up with him since his grandpa offered me to be his girlfriend. I tell my boyfriend that he could never satisfy me and that his grandpa has better stamina in spite of his age. I am going to live in this house from now. But good news are that my boyfriend’s grandpa allowed my boyfriend also to live here. He will have to listen to both of us fucking every night, he'll see garbage cans full of giant, overflowing condoms, having to watch us kiss and pet each other at dinner, etc. All the humiliating aspects of having to live in this situation. The last scene is implied to be 2 weeks later than the previous. I search for food in the kitchen while notice my ex there. I tell him how amazing was the vacation which his grandpa arranged for me. We spent time in the beach and all young men were jealous of his grandpa because he owns a young woman like me. But when they saw his huge bulge they weren’t confused anymore. I laugh about all the men staring at the grandpas giant cock, clearly jealous. "It was almost..... primal. Like he was an alpha asserting his dominance with his giant cock." Eventually we got so horny, we fucked on the beach, laughing at all the young cuckolds watching us. After he covered me in a giant cumshot, I didn't even clean up and continued walking down the beach covered in cum. "An old man marking his territory so all the young men know who I belong to." I laugh about the story and mock young men/worship old men some more before saying the story has made me horny and I am going to go fuck my ex’s grandpa again.