United Kingdom, Sept. 7 -- Matthew McConaughey had "no idea" his son was interested in acting.

The Oscar-winning star's eldest child Levi, 17, makes his feature film debut opposite him in The Lost Bus but the 55-year-old actor admitted he initially ignored the teenager's requests to audition to play his son in the movie.

Matthew - whose mom Kay McConaughey, 93, also appears in The Lost Busy - told E! News: "He's introducing himself and I happen to be alongside him and in some of the same scenes of him which is pretty cool.

"Three generations. My mother has always been a performer and so she's been films. I had no idea he was even interested.

"He came back four times asking me, 'Can I read for it?"

Matthew pitched his son to the casti...