I have found myself using this in a variety of situations.
1) I recently cut someone out of my life for a variety of reasons. I still see him from time to time as we are both with the same theatre troupe (yes, when I see him, I am polite and professional but I do not engage. I have also kept my personal feelings about him to myself). He attempted to pester me about why I no longer spoke to him and I said "That topic is not open for discussion". Similarly when he used the "use mutual acquaintances (and always the drama queens who live on drama on gossip) to guilt me into talking to him". I said "That topic is not open for discussion"
2) When people pry into my personal life: "That topic is not open for discussion".
3) When people attempt to involve me gossip: "That topic is not open for discussion". Or: "I think that's between them" and walk away.
I am ashamed to admit I used to be a HORRIBLE gossip and a "Woe as me pity party drama queen". Now I am very conscious of that and have worked very hard to change.*
Anyone else used this or something similar?
*Heehee, a little too hard maybe, my friends now have to fuss at me "Pixie, we're your FRIENDS, you CAN tell us when your sad, it's OKAY".