One house having multiple cars on the street

I understand it is public parking however we have a new neighbor who has maybe 15 cars taking up our street for a gathering.

We have one guest coming over later and there is no room in front of our home for them. Any one know if there’s anything we can do or any laws or for this? My fiancé went over to politely ask for that one spot to be open but they owner said it was public parking and shut the door.