Any of our photographers know why this happens? Or, maybe I need to stop drinking?

A wide angle lens exaggerates perspective. That, combined with the camera probably being held somewhat below eye-level, will make even slightly more distant objects (or people) appear smaller than they would to your eye. In the first group shot I appear shorter than Orla (because I'm farther away) but in the second I appear taller (because she's farther away). With a wide-angle lens it only takes a slight difference in distance to make a big difference in apparent size.