When a woman wants to have intimate relations with an older man, especially when that man is a cuckolded husband or otherwise less-than-capable partner. Also could be an old, trusty dildo that's well-used.
She was bored with her household chores, so instead chose to slide down the dinosaur.
Leave work right at quitting time, regardless of whether you're in the middle of a project -- like Fred Flintstone in the opening sequence of every episode of the Flintstones. (Shouting "Yabba dabba doo!" is optional.)
Clear paper jam? Heck with that! It's five o'clock -- time to slide down the dinosaur.