Let Oneself Go

Dictionary

let oneself go
phrase

1. act in an unrestrained or uninhibited way.
   "you need to unwind and let yourself go"
   
   
2. become careless or untidy in one's habits or appearance.
   "he's really let himself go since my mother died"

Teaching English or American idioms to people who don't speak English as natives can be challenging. Idioms also need to be presented in context. Idioms may also change over time.

I used this expression not too long ago in describing my g*dson's ex-wife. She's been on the lookout for a new husband. She also grew big. "Boy, she really let herself go!" I said to the woman's ex-mother-in-law (my primary friend).

"What's that supposed to mean?" my friend asked.

"You have to ask? She got fat!"

I suppose one could be more discreet or diplomatic. My Mother used to say, "Well, she's got a good appetite," or "She looks like she's a good eater!"

Oh well... I remember studying other languages and having to learn such phrases. What a challenge!