That makes a lot of difference in most jurisdictions.
When my next door neighbor started running a dive on her balcony I turned her in.
Lest you get all tangled up in your boot stomping and clothes rending, she'd earlier filed a complaint with the board of health about my backyard garden!
Yup, I passed muster, and she didn't.
So, did they serve wine or distilled beverages?
I understand, mate, however at least at most of the gatherings I have attended if you did not bring something to contribute to the get-together then something contributed monetarily to assist with the expenses was not without merit. For friends, an invite to one of _their_ get-togethers was acceptable in return. I do not recall reading that these people were putting the meal together in order to generate a profit, therefore such an event falls under the ‘private’ label. At least as I understand it from the few legal professionals I have discussed matters with.