What is fly in the lotion?

The phrase "fly in the lotion" is typically used to describe a small but noticeable problem or flaw that ruins an otherwise desirable situation. The phrase comes from the idea of a fly landing in a jar of lotion, which would make the lotion unappealing to use. This phrase is often used in situations where a small mistake or problem distracts from an otherwise successful performance or event. It can also suggest that something is not as perfect as it seems and that there may be hidden flaws beneath the surface. The phrase is often used in informal conversation, particularly when discussing minor but noticeable problems or flaws.