1.
Brian Bonsall was only 11 years old when he filmed a literal makeout scene with a grown woman in Disney’s Blank Check. He had just turned 12 when the movie came out, and Karen Duffy, the older woman, was just shy of her 32nd birthday.
2.
Mila Kunis was only 14 when she lied about her age to get cast on That ’70s Show. She was 15 when it came time to film her first-ever kiss, and costar Danny Masterson bet Ashton Kutcher — who was 20 at the time — $10 to French kiss her with tongue.
3.
Keira Knightley was 17 when she filmed Love Actually. She played a married woman in the movie and was 18 when it was released. Her onscreen husband (Chiwetel Ejiofor) was 26, and the home-wrecker (Andrew Lincoln) was 30.
4.
Trina McGee was 28, married, and a mom in real life when she first appeared as Angela, a junior in high school, on Boy Meets World. Rider Strong, aka Shawn Hunter, played her love interest, and he was only 17 at the time.
5.
Taissa Farmiga was 16 when she started filming American Horror Story: Murder House. She had her 17th birthday just a few weeks before the series premiered, and her onscreen love interest, played by Evan Peters, was 24 years old.
6.
Hilary Duff filmed A Cinderella Story when she was only 15 years old, and she turned 16 when the movie was released. At that same time, her onscreen boyfriend, Chad Michael Murray, was just shy of his 23rd birthday.
7.
Emmy Rossum turned 17 a couple days before production started on The Phantom of the Opera, while the two men who vied for her love, Patrick Wilson and Gerard Butler, were 30 and 33, respectively.
8.
Frankie Muniz was just 17 when his Malcom in the Middle character started dating Reagan Dale Neis, who was 26 years old at the time.
9.
Maitreyi Ramakrishnan is more than a decade younger than her onscreen boyfriend in Never Have I Ever. She was 17 when she was cast and 18 when the series premiered, and at that same time, Darren Barnet was 29 years old.
10.
Danielle Campbell was 14 when she started shooting Disney Channel’s Starstruck. Her love interest in the movie, played by Sterling Knight, was 20 years old.
11.
Katherine Heigl was only 14 when she filmed My Father the Hero. She had just turned 15 by the time the movie came out, and her love interest, Dalton James, was just shy of his 23rd birthday.
12.
Keira Knightley was only 17 when she filmed that kissing scene in the first Pirates of the Caribbean movie, and Orlando Bloom was 25.
13.
Taylor Momsen was only 15 years old when her Gossip Girl character started getting romantically involved with 23-year-old Chace Crawford’s character.
14.
Corbin Bleu is the youngest core cast member from High School Musical. He was 16 years old when they filmed the movie, but Monique Coleman was literally 25.
15.
Cameron Monaghan is nearly a decade younger than his onscreen husband, Noel Fisher, in Shameless. Cameron was 16 when they started filming and 17 when the series premiered, while Noel was just shy of his 27th birthday.
16.
Aimee Teegarden was only 16 when she started filming Friday Night Lights. She was newly 17 by the time her character got into a romantic relationship with Zach Gilford’s character, and he was just shy of his 25th birthday.
17.
And finally, Selena Gomez was a full decade younger than her love interest in Another Cinderella Story. She had just turned 16, and Drew Seeley was literally 26 years old.
Source: https://www.buzzfeed.com/spenceralthouse/hollywood-children-and-adult-age-gaps