(as) smooth as a baby's bottom simile
The adjective "smooth" can be replaced by "soft".
Used to describe that something is extremely smooth, clean, soft and silky to touch
This fur carpet is too expensive, but it is as smooth as a baby's bottom. Do you feel that?
She is going on a healthy diet. That's why her skin is as smooth as a baby's bottom.
To help something run or work smoothly or successfully
1. (adj) (Used to describe one's manner or movement) fast, smooth, or skillful.
2. (adv) Fast, skillfully, or smoothly.
1. Used to indicate the water in a state of calm and tranquility.
2. Used to indicate some solid surface that is very smooth.
To smooth something.
This simile is first attested from the mid-20th century and sometimes appears “as soft as a baby’s bottom”. It is unknown who coined the expression.