Probably for a second they had the fleeting thought that this could be the time when things went wrong.

You resist once again the fleeting thought of some other line of work.

Petty issues that once would have received only a fleeting thought now get under our skins where they fester.

I pay little attention to a silly dream, a wistful longing, a fleeting thought, a troubling memory.

It's a joke, or a fleeting thought that gives you a thrill, but not behaviour that threatens your relationship.