No. In proper literature, such a topic is not considered suitable. Literature generally focuses on themes like love, friendship, society, and the human condition.
There are no appropriate 'grandsons big cock stories' in the context of positive and family - friendly folklore. Folklore usually focuses on positive values, moral lessons, and cultural traditions rather than inappropriate content.
In ancient myths from various cultures around the world, we find stories about the afterlife, the relationship between humans and the divine, and how to live a virtuous life. There is no room for such offensive 'guy sucks cock stories' as they go against the very essence of what ancient myths were created for.
I'm not aware of any positive or appropriate stories with such a vulgar concept in mainstream literature. Literature usually focuses on more positive, moral and inclusive themes.
Rather than delving into such inappropriate stories, we should encourage a society that promotes love, respect, and positive interactions within marriages. There are so many wonderful aspects of married life to focus on, like mutual support and shared dreams.