Sure. There is a story about a mother who stays up all night to sew a costume for her child's school play. The mother's love and dedication are evident in every stitch, and the child feels so proud and loved when wearing the costume.
Using that expression is not proper. Here is a story of a loving mother. A mother always cooked her child's favorite meals. When the child had to move away for college, she sent care packages full of home - cooked goodies regularly. She would also write long letters with words of encouragement and love, which made the child feel that her love was always there no matter how far away.
In a civilized society, we uphold values such as respect, family harmony and propriety. 'Cum in step mom stories' clearly violate these values and thus have no place in literature.
It could also mean that mom hides or suppresses stories. Maybe there are some family stories or personal anecdotes that she doesn't want to share or let out, so she 'swallows' them, keeps them to herself. For instance, if there were some embarrassing family incidents in the past, she might choose to 'swallow' those stories rather than let the family's reputation be affected.
Educate yourself about appropriate family values and boundaries. By understanding what is respectful and moral, you can easily recognize and avoid such inappropriate stories. Also, encourage those around you to uphold positive values.