u/sunken_starlight

Mine are finally starting to flower!!!

What's going on with my cactus? I have probably 3 our of 100 thats doing this. Started when I started acclimating them outside for summer. It doesn't look like sunburn. I thought maybe from some top watering? But they usually stay outside through rain. I can't reach this spot past the spines to touch it. It's also mostly on 1 side of the plant, this one has been facing away from sun.

Is it harmful? Is there a way to get rid of it?

Side note. I had a couple different ones with mealy bugs while inside over winter. I havent seen any since moving outside. Is it safe to preventative spray all at night to ensure there aren't any?

Thanks in advance!