Les invités de mon père (2010)

Lucien Paumelle has been a human rights activist for decades and his relatives are not astonished when he announces that he is determined to help illegal immigrants by giving them shelter in his apartment. But they are downright appalled when they meet the undocumented aliens for the fist time, a little girl named Sorina and mostly her mother, Tatiana, a twenty-eight-year old sex bomb. To make matters worse, Lucien offhandedly tells his next of kin that he has just … married Tatiana. How will Arnaud, his son, and Babette, his daughter, react?

IMDB

An interesting glossy French bourgeois comedy that has serious overtones. This is a study of the blindness of do-gooding, the selfishness of an old man, seeking to rediscover his youth, the limits of charity. A wealthy man, a retired doctor, takes in an eastern European woman and her young daughter and marries her so she can work in France and eventually have secure status. Little by little he falls in love with her and they become sexually involved despite the great gap between their ages. From the beginning the man's daughter and son find the woman offensive, crude, annoying.

(The storyline reminds me the funny book called "A Short History of Tractors in Ukrainian" which I once shared here as an audiobook in German. Same collision - an ex-USSR "gold-digger" vs a Western old man who found his "happiness" :))