Zinloos (2004)

Successful consultant Martin is investigating a case of mismanagement at a Dutch municipality; in his private live things aren't even going that well. He suspects that his girlfriend Carina is cheating on him, and he is getting stalked by a certain Frits Bleekemolen. When Martin finally agrees to an interview with him, all he gets are awkward questions about his personal situation and he throws him out of the house. Frits doesn't give up though, and confronts Martin again. When he finds out that Carina took Frits on a cleaning job, he loses his temper. Martin tries to cover up the evidence, a decision he will regret.