I can’t say I’ve always told my kids the truth or not - but I try to. My wife is better at that.
My two girls are in 6th grade, and according to the parents, some of their friends still go along with believing in Santa. Hard to say if they really do though!
My one daughter figured it out in fourth grade, and my other daughter figured it out just last year (end of fifth grade).
I remember when they were younger and they figured out about the Easter Bunny (or was it the tooth fairy?). They weren’t too upset, but after thinking about it for awhile the one got a real sad look on her face and said “Does that mean Santa Claus isn’t real either?”
Thinking fast I replied: “You know all that stuff you get on Christmas? Do you think mom and I would be buying you all that stuff?” She looked at me like I was nuts and said “NOOOO!” and walked away with a big smile on her face! That gave us another two years or more!
This year we were setting out the stockings, etc. She looked at me and said “So - you put ashes all over the carpet for Christmas morning!?” She just shook her head like I was nuts (again!). I figure I should probably do that again this year just to carry on the tradition of being grumpy at ol’ Saint Nick for messing up the carpet so much!