One possible story could be that there was a baby who was playing near the sleeping mom. The baby had a soiled diaper which was giving out an unpleasant smell, like what you might crudely refer to as 'asshole smell'. And the baby was making little noises that the mom was still sleeping through.
Well, it could be that while the mom is sleeping, a pet might have accidentally passed gas near her, and that's the source of the 'ass smell'. Maybe the family dog had some indigestion and let out a stinky toot right beside the sleeping mom.
First, try to find the source of the smell quietly. If it's a pet - related issue, gently move the pet to another area. For example, if it's a cat that's the culprit, pick it up carefully and put it outside the room.
Once, my mom was so tired from working all day. She sat on the couch to rest while I was doing my homework. I finished my work and went to the living room to find her fast asleep with a book on her lap. I took a picture to tease her later. When she woke up, she was a bit embarrassed but we both had a good laugh.
Once upon a time, there was a mom who had a really tiring day. She had been to a party and had a bit too much to drink. When she got home, she just collapsed on the couch and fell asleep. Her little child tiptoed around, not wanting to wake her. The child covered her with a blanket and sat nearby, reading a book quietly, waiting for mom to wake up on her own.
I'm not sure specifically which'sleeping with mom story' you are referring to. It could be a story about a child sharing a bed with their mom for comfort or during a special situation like a thunderstorm when the child gets scared.
It could be that the puppy fell asleep at mom's feet. You saw this as an opportunity to have some quiet playtime with it. You might have gently rubbed its belly while it was sleeping, and the puppy just made a little whimper in its sleep, which was really cute.
Mom and dad might sleep alone because they prefer different sleeping temperatures. Maybe mom likes it really warm while dad likes it cool. So, to be comfortable during the night, they choose to sleep in separate rooms.
Well, if it's in a more emotional context, it might be that the person touches their sleeping mom as a way of seeking comfort. For example, a child who had a bad dream might reach out to touch their mom's hand while she's sleeping, subconsciously looking for that sense of security that moms usually provide.