
Jim N. answered 07/27/19
Patient, knowledgeable photography tutor
If you don't save in Photoshop, Lightroom shouldn't create a copy. I just did a test with Lightroom Classic and Photoshop, and that was the case--I closed the image in Photoshop without saving, and no copy was made.
If you're still having this issue: what version of LR and P are you using?