beside the cushion
Unimportant. A digression. Oh, that's beside the cushion. Let's get back to the main topic.
miss the cushion
To fail in some way. The phrase is similar in meaning and use to "miss the mark." I felt confident going into the interview, but I think I really missed the cushion, judging by the recruiter's facial expressions.
cushion the blow
To ease the pain or stress of something unpleasant. When my daughter had to get a shot at the doctor's office, I tried to cushion the blow by telling her we would go out for ice cream afterward.