Because you ALSO once again planted that old "I'm a mental health counselor" flag in an effort to shore up your bona-fide's on how to deal with teens (as you have on many other topics in the past), until I've called you out on it, only to have you roll it back, responding, and I quote, "I'm not really a therapist, remember?" if that's true, then then stop acting like one and putting it forward as a shield to defend your position.
And if you are a father of two teens, you should still know better that they are keeping things from you, no matter how serious or innocuous the subject matter may be. Any parent who thinks that a false statement is lying to themselves and anyone else to whom they try to convince otherwise.