Idiom used in frustration/anger, sounds like "je nie kochamy"?

In moments of frustration with students, some Felician nuns I had in grade school would say something that sounded like "yeh neh koHANeh." I assumed it was a popular Polish idiom, but I haven't been able to find it used in the same sense online or in any printed lists of idioms. "They do not love" or "It's not love," the closest I could come based on guesses about what the actual words were, sound much milder than than what I always assumed the nuns were saying, but perhaps this is the Polish equivalent of calling someone a "son of a gun" -- that is, watering down a cruder idiom?

I would appreciate any help in figuring out: a) what the actual words were, b) what the literal and idiomatic meanings are, and c) whether this is a euphemism for some other, harsher saying.

Hm, maybe "To nie kochanie" (?) - it's not /real/ love. But I'm not sure if it's an idiom, it depends on the context.

Jeny kochany is a mild euphemistic curse used instead of Jezu kochany (dearJesus). Taking the Lord's name in vain was once a serious misdeed and/or faux pas, so similar-sounding formulations were concocted instead.

Other common Polish euphemisms include: ja pierniczę (pierdolę), kurczę (kurwa), mam to w nosie (w dupie); pocałuj mnie tam, gdzie słońce nie świeci (w dupę), etc.

English is full of such euphemisms: Gosh instead of God, geez (Jesus), blimey (God blind me), cripes (Christ), goldarnit (God dammit), son of a gun (son of a *****), etc.

Thanks! Something like "oh my gosh" would fit exactly the contexts in which I head the nuns say this. (Now that I know how it's spelled, I can see that you've had to explain this before. Sorry for the repetition.)