Playing mind games and playing with someone heart is SO wrong. You want him/her tell them and do something about it... "punishing them" for past mistakes is so wrong. Case of I don't want him but don't want anyone else to have him. Don't be selfish.
"That's great for you, but for me this is my future. How we perform now- each and every one of us, because I'm in charge of this team and how well you do reflects on my skill as a leader- decides whether or not I have a future in the profession, and whether or not I have a future in the profession... well, that decides whether or not I have a future in my family."