Why do narcissists devour so much sugar (candy, ice cream, donuts, etc., in huge amounts at a time)?

I feel that her weight is the ONLY objective metric of an underlying mental disorder. Anything else can be lied about. Who me? I never did that, i never said that, oh that was a joke, oh that is a misinderstanding, lies, lies, lies.

At my home i purposely bought a container of those delicious mini brownies at Costco and put them conspicuously out on the counter one evening as a test. In the morning about 1/3 were gone. I'd guess about 15 brownies. I did not know what NPD was at the time just observing an odd abusive pattern of behavior toward me and herself. This behavior included her climbing into my bed on top of me while i slept. Hysterical screaming at me was another strange behavior I endured.

A PwNPD typically engage is some form of self indulgence. This behavior stems directly from emotional dysregulation and manifests as a pattern of self soothing many times self destructive activites. Over drinking, over eating, over the top anger, provocative to others, over selfishness, hoarding, manipulative, porn addiction, sex addiction, over exercising, overdoing plastic surgeries, 40 cats, drug addiction, dictating, dominating, speeding in cars. Out of bounds behavior. My aunt waddles around, grotesquely obese, wears clothes that look like a table cloth. Screams out in a childlike baby voice at family gatherings "Who's going to eat with ME!!!". Looks like an animal eating voraciously hunched over her plate. Looks around at other peoples plates "are you going to eat that?". Looking to eat others food. I bought chinese take out one time. "Is that all the food you bought?" Violently hiccups after gorging her stomach with food. Every single day i have been around she exclaims "i didn't used to be so fat and ugly" and "i used to be beautiful and slender". Sometimes twice a day. A message to anyone "don't look at reality of myself imagine me as i imagine myself in my delusions."

How did it feel when experiencing gay sex for the first?

Understand what you are dealing with, study the machinations, learn the narcissistic patterns of behavior. Love yourself and be yourself.