Coworker thinks he has the right to take over for someone who is on their honeymoon

I have a coworker who everyone at the office calls The Vulture, not like the Spider-Man villain more he tries eavesdropping on everything he can and once he learns someone is going on a vacation or is out sick he will try to swoop in to take claim to the persons routine while they're gone. I work for a gym so the world of fitness training is pretty competitive. Recently my bosses daughter just got married and another coworker who the daughter (who also works for the gym as a trainer) put in charge of taking care of her morning cycling class did such a good job the boss asked her to fill in till her daughter returns from her honeymoon as that trainer usually teaches the morning cycling class on weekends and coworker accepted.

The Vulture saw that the coworker took over the other day and got infuriated that the coworker who was picked was not him. He today left a note on my door before I arrived and when I arrived I found it and read it. The note read, "I know you made sure 'coworker' stepped in and took over for 'bosses daughters name'! you just didn't want me anywhere near your precious routine of morning cycling classes!" Now for context me, another coworker who teaches the second morning cycling class and bosses daughter who teaches the third class we have a system that works that nobody can ever fully replicate because we trust in each other and we have taught few others who do cycling classes out techniques. For Vulture unfortunately this was one swoop he did not fly in fast enough to try to work his supposed charm he claims he has and all week so far bosses daughters one on one trainees she trains they all have told Vulture to back away because they are loyal trainees to her only.

I gave my boss the note and just before I typed this post I heard over the PA System, "Will Vulture please come to my office NOW!" I can only imagine the talk he and my boss are having while I get to go on my lunch break.