not go there
not (even) go there
To not pursue, explore, or continue a topic of conversation. Used humorously, the phrase usually implies that the speaker has a potentially scandalous, sensitive, or otherwise complicated association with the topic. Steve: "I heard you once had a crazy party with a bunch of the Hollywood A-listers—what was that like?" John: "Don't even go there, Steve, that was a crazy night best left to the imagination!" A: "So, do you ever hear from your ex-husband?" B: "Let's not go there. That divorce trial still gives me a headache!"