2022 - What's made you happy today

A very small cutting I took (stole) of nextdoor's penstemon, which has subsequently died of neglect, his not mine, are you keeping up, has flowered. It was a bit hit and miss because I also neglected the cutting, but although it is only about 5" tall on one stem it has thrown out a couple of flowers. It's the first penstemon I've ever grown and it's very pretty.

Question- should I cut the flower off (I hate doing that) to conserv energy or can I leave it alone?