HER FATHER, MY LOVER (2015) & His Father, My Lover

Here's IMDb's storyline for Her Father, My Lover (2015) [友だちのパパが好き]:

An eccentric young woman falls in love with her sensible friend's flaky father and pursues him with no regard for the consequences, dragging others unwittingly into an inescapable emotional vortex.

And here's the film synopsis from Festival Scope:

“You're a sicko”. University student Taeko is appalled by her kooky friend Maya's attraction to her father, Kyosuke. His affair with [young] workmate Hazuki resulted in her pregnancy. His subsequent divorce from cancer survivor Midori, only encourages Maya further. Meanwhile, her jilted lover Tadokoro, who also happens to be her former high school teacher, begins to stalk her. Maya's obsession with Kyosuke sets off a chain reaction of imploding relationships, and all Taeko can do is watch...

In summary, Maya, à la Angela in American Beauty (1999), desperately wants to have an affair with Kyosuke, Taeko's much older father - especially after Maya learns that Kyosuke is being divorced, because he impregnated his much younger workmate. In addition, Maya, a Japanese university student, is being stalked by Tadokoro - her deserted lover and former high school teacher. 

"[...] you fucked my dad?"\YouTube

I wouldn't be surprised if Kenji Yamauchi's screenplay was based on a real-life situation, because, like Carissa Culiner shared on Live From E!, "[...] People have hot dads." And consequently, like Maya, some teens and young women have sexual affairs with their friend's and\or boyfriend's dads.

For example, in the YouTube video, "[...] You Fucked My Dad?", a boy asked his blond ex-girlfriend, "I'm I just supposed to overlook the fact you fucked my dad?" And Olivia Elgart posted on the Daily Mail: "Now THAT'S a love triangle! 19-year-old girl confesses to sleeping with her ex-boyfriend's 56-year-old FATHER in a sordid online post"

It's a fact that DILFs and the Daddy Thing is a thing for (some) teens.