If left alone for a few days it would just wither up and fall off by its self,
Nice looking cactus though, do you know what kind it is.

Thank you :)

I don't know sorry, I was given it second hand.

The growth is part of the flower itself. It seems you were not there to see it bloom. You missed something special. I would mention however, your cactus needs sufficient light and a fast draining potting medium to grow well.

Here is a photo of my Echinopsis subdenudata in bloom. You can see how large the flowers are. But they only last about a day.

Christopher

You had a nice bloom there!

I would suggest a clay pot and special cactus mix for your plant if you ever decide to repot it. At the very least, never let it sit in water in that little white dish under it. And be careful not to overwater, but you probably know that.