MTV released the trailer for the upcoming sixth season of its hit reality TV series "Teen Mom OG," MTV reported. The four original stars, Farrah Abraham, Amber Portwood, Maci Bookout and Catelynn Lowell, return and there are wedding bells, wedding blues, custody battles and explosive arguments in store.

The trailer begins with an argument between Portwood and her ex-fiancé Gary Shirley, who is the father of her 7-year-old daughter Leah.

"There is nothing for you to say to me," Portwood, 25, says. "Nothing is wrong."

The clip then cuts to a shot of her kissing Leah, then a shot of her crying over her custody battle with Shirley.

"I shouldn't have to go through a custody battle for my kid," she cries.

Catelynn Lowell and Tyler Baltierra are finally tying the knot after years of dating and two children together. Catelynn, 23, tries on her wedding dress in one clip, but she's shown in another shot crying to her 23-year-old fiancé, worrying about whether they're making the right decision in taking the next step in their relationship.

"You know some people get married and everything changes," she cries.

Lowell's mother wonders if her daughter's nerves and emotions are due to post-partum depression, since the wedding ceremony takes place shortly after Lowell gave birth to their second daughter, 11-month-old Novalee Reign. The couple also shares 6-year-old daughter Carly, who was placed under adoption.

But it doesn't look like wedding bells will be ringing soon for Maci Bookout, even though the 24-year-old wishes her boyfriend Taylor McKinney would pop the question. McKinney moved in with Bookout, and the couple announced they were expecting their first daughter together, Jayde Carter, during season five. Bookout shares 7-year-old son Bentley with her ex-fiancé Ryan Edwards.

"I want to be his wife, make me your wife," Bookout says, sounding frustrated.

Abraham gets into yet another argument with her mother in one scene and also visits her late boyfriend Derek's grave, who is also the father of her 6-year-old daughter Sophia. But in the last clip, Abraham has an explosive argument with a "Teen Mom OG" executive producer.

"I don't need to be a part of a trashy-ass show anymore, cause I make millions of dollars doing other sh--," she yells. "What a dumb, twisted mother f----r."

See the full trailer below and be sure to tune into the season six premiere of "Teen Mom OG," airing Monday, Jan. 4 at 10 p.m. ET on MTV.