You haven't been able to ever satisfy your GF, and one night, sexually frustrated and not getting anywhere with your loser cock, she turned to her Step-Brother for comfort. And that's when it all started. She gave you an ultimatum. To be a cuck every night, watching them fucking, sitting in your cuck chair and jerking off, never getting pussy again, or breakup.
You love her, you never want her to leave. So now you spend every night watching your GF sucking and fucking a huge cock that belongs to her own Step-Brother, knowing there is nothing you can do about it. A real man would stop it. A real man would be able to satisfy his GF. But you're a pathetic loser cuck, and you jerk and cum, like the pin dick beta you are.
