Jax, 37, opened up to Bravo's The Daily Dish podcast about how Nick, 36, allegedly refused to take a photo with him recently in order to promote their mutual friend's hotel nightclub in California.
Jax recalled of the moment Nick shot him down, "I go, 'First of all, buddy, don't toot your own horn, I have no f-cking idea who you are.' I know you're on The Bachelor -- okay, good for you, great. You're on a disposable reality show that you'll be gone in five minutes and no one will know who you are, so you want to get your five minutes of fame in now."
Jax said that Nick gave him a lame excuse for not helping out his friend, saying he doesn't use social media.
"Well, you're a f-cking piece of sh-t," Jax claimed he had told Nick during their heated exchange at the nightclub. "Your friend brought you here as a favor to help him out, you're gonna act like that? You're a f-cking d-bag."
Jax told The Daily Dish the conversation wasn't pretty, especially since alcohol was involved.
"I just think he's a d-bag," concluded Jax, a 37-year-old model and actor.
Nick's season of The Bachelor wraps Monday, March 13 with a two-hour finale, followed by the season's After the Final Rose special at 10PM ET/PT on ABC, which will feature a historic moment.
Nick still has two bachelorettes in the running for his heart: Canadian special education teacher Vanessa Grimaldi and Arkansas boutique owner Raven Gates.
After his The Bachelor stint ends, however, Nick has no intention of leaving the spotlight. The former software salesman-turned-entrepreneur joined the Season 24 cast of Dancing with the Stars.
Nick will be paired with pro partner Peta Murgatroyd when the reality dancing competition returns to ABC on Monday, March 20 at 8PM ET/PT.