Kevin Costner gets emotional hearing how much fun his son Hayes, 15, had working with him on the set of Horizon

Kevin Costner got emotional hearing how much fun his son Hayes Logan Costner had working with him on the first chapter of his $100M-budget four-part western Horizon: An American Saga.

'It was so fun, just working with my dad, I loved [it],' the 15-year-old high schooler gushed to Access Hollywood at the LA premiere on Monday.

'And he just taught me everything. He was there directing me by [my] side, and it was just amazing to watch him direct because I'd never seen it before. I've only seen him act before.'

Considering the 69-year-old Yellowstone alum primarily cast Hayes in order to spend quality time with him, he spent a good 30 seconds looking misty-eyed at what he had said on the red carpet.

When Access' Scott Evans asked Kevin how he felt right then, he quietly said 'good' before sheepishly putting dark sunglasses over his teary eyes.

The 15-year-old high schooler gushed to Access Hollywood at the LA premiere on Monday: 'It was so fun, just working with my dad, I loved [it]'

Costner fully admitted he 'trapped' the avid surfer - who was 13 at the time of filming - and cast him as the character Nathaniel Kittredge, who defends his family from a home invasion in the opening scene.

'I did. I figured out how to have him close,' the twice-divorced father-of-seven told ET on Monday.

'He's never going to look this young, he's never going to look this sweet and handsome. He's just going to grow into a young man and he's really good in the film.'

Hayes chimed in: 'I got to spend the whole day with him every day and just see him work...I had such a blast. I just thought it was really cool and it was an amazing experience.'

Kevin has 'shot about 13 days' of the final two Horizon films, but before they continue filming in August, Hayes is looking forward to a family vacation next month: 'I think we're going to the Bahamas soon and I'm glad.'

Costner was also joined at the Regency Village Theatre in Westwood on Monday by his 17-year-old son Cayden Wyatt Costner, 14-year-old daughter Grace Avery Costner, 40-year-old daughter Annie Clayton Costner, and 36-year-old son Joe Tedrick Costner.

The two-time Oscar winner also convinced his son Joe to portray a mystery role in the third chapter of Horizon after previously having small roles in his films Tin Cup (1996) and The Postman (1997).

Kevin had planned on casting his daughter Grace as the character Elizabeth, but she wanted to be a normal child and didn't want to leave her friends or school behind.

Hayes continued: 'And he just taught me everything. He was there directing me by [my] side, and it was just amazing to watch him direct because I'd never seen it before. I've only seen him act before'

Considering the 69-year-old Yellowstone alum primarily cast Hayes in order to spend quality time with him, he spent a good 30 seconds looking misty-eyed at what he had said on the red carpet

When Access' Scott Evans (L) asked Kevin how he felt right then, he quietly said 'good' before sheepishly putting dark sunglasses over his teary eyes

Costner fully admitted he 'trapped' the avid surfer - who was 13 at the time of filming - and cast him as the character Nathaniel Kittredge, who defends his family from a home invasion in the opening scene 

The twice-divorced father-of-seven told ET on Monday: 'I did. I figured out how to have him close. He's never going to look this young, he's never going to look this sweet and handsome. He's just going to grow into a young man and he's really good in the film'

Kevin has 'shot about 13 days' of the final two Horizon films, but before they continue filming in August, Hayes is looking forward to a family vacation next month: 'I think we're going to the Bahamas soon and I'm glad'

Costner was also joined at the Regency Village Theatre in Westwood on Monday by his 17-year-old son Cayden Wyatt Costner (2-L), 14-year-old daughter Grace Avery Costner (3-L), 40-year-old daughter Annie Clayton Costner (2-R), and 36-year-old son Joe Tedrick Costner (R)

The two-time Oscar winner also convinced his son Joe to portray a mystery role in the third chapter of Horizon after previously having small roles in his films Tin Cup (1996) and The Postman (1997)

Kevin had planned on casting his daughter Grace as the character Elizabeth, but she wanted to be a normal child and didn't want to leave her friends or school behind

Costner pays his ex-wife #2 Christine Baumgartner (2-R, pictured in 2019) $63K/month in child support to help care for their three children after settling their contentious divorce battle on September 19 - five months after their legal separation following 18 years of marriage

Costner - who named his character Hayes Ellison after his son - spent $38M of his own money and mortgaged a beachfront property in Santa Barbara in order to help fund his epic, set before and after the Civil War 

The first chapter of Horizon: An American Saga hits US theaters this Friday and the second chapter hits US theaters August 16

Worryingly, Chapter One currently has a dismal 47% critic approval rating (out of 38 reviews) on Rotten Tomatoes

Costner pays his ex-wife #2 Christine Baumgartner $63K/month in child support to help care for their three children after settling their contentious divorce battle on September 19 - five months after their legal separation following 18 years of marriage.

The Emmy winner fathered Joe and his daughters Anne and Lily during his 16-year marriage to ex-wife #1 Cindy Costner, which ended in 1994.

Kevin also has a 28-year-old son Liam with his ex-girlfriend Bridget Rooney.

Costner - who named his character Hayes Ellison after his son - spent $38M of his own money and mortgaged a beachfront property in Santa Barbara in order to help fund his epic, set before and after the Civil War.

The first chapter of Horizon: An American Saga hits US theaters this Friday and the second chapter hits US theaters August 16.

It features Sienna Miller, Sam Worthington, Jena Malone, Michael Rooker, Danny Huston, Luke Wilson, and Jamie Campbell Bower.

Worryingly, Chapter One currently has a dismal 47% critic approval rating (out of 38 reviews) on Rotten Tomatoes.