Der Nesthocker (2018)

Armin has virtually abandoned any hope of finding happiness in the perpetual struggle of life - until he meets the woman of his dreams at last. Everything with Tina could be simply perfect - if it weren't for her son Hendrik, a 25-year-old failed artist with a looming presence who still lives at home and won't tolerate another man anywhere near his beloved mummy. Soon Hendrik declares war on Armin, who has no choice but to engage in a bitter though surreptitious struggle with Tina's unpleasant offspring, if he wants to keep the woman he loves.