Heather Marter, Dustin Zito, Tyler Baltierra and Catelynn Lowell on the set of VH1's "Couples Therapy"

By Lilit Marcus

Season 3 of "Couples Therapy," featuring four former MTV stars, starts tonight at 10/9c on VH1, and while we're banking on series staples like intense therapy sessions, shouting matches and buckets of tears, we can't help but wonder what issues might come to light for Heather Marter, Dustin Zito, Tyler Baltierra and Catelynn Lowell. After watching the trailer below, we noticed a few familiar points of contention that seem to remain unresolved for our "Teen Mom" and "Real World" casties. Here are some things we're expecting to see as these young adults work on healing their relationships:

Dustin's gay porn past

The first words we hear from Dustin in the video are, "I was in the porn industry." Might as well hit the ground running. While he was open with Heather about it (after she found out from her own mother!) during "Real World: Las Vegas," Dustin's ability to talk comfortably about his ex-career has clearly evolved over time. However, despite the strides he's taken in working through his demons (and the fact that D&H claimed to have moved past it after "Battle of the Exes") it's clearly still a sore spot for the couple.

Catelynn and Tyler's daughter

Though Catelynn and Tyler aren't raising any children right now, the "Teen Mom" affiliation is something that'll stay with them forever -- even "Girls Gone Wild" creator (and fellow "Couples" cast mate) Joe Francis tells Cate straight up, "I'm going to call you 'Teen Mom.' That's your name." (Back off our girl, Joe!) The moment these two chose to make an adoption plan was one of the most tear-jerking in MTV history, and though they currently have a great relationship with Carly and her adoptive parents, the pair will always wonder what life would have been like had they made a different decision. Expect that story to come up -- and make sure you have tissues nearby when it does.

Heather’s amazing facial reactions

On a lighter note, Heather Marter has one of the best bitch faces we've ever seen (second only to Sadie Saxton, of course) and she could always be counted on for a well-placed stink-eye every time one of her housemates did something crazy in Vegas. Considering she's about to become housemates with Flavor Flav, we think her reaction shots are about to see a major renaissance.

Catelynn and Tyler's wedding

It's well known that the "Teen Mom" power couple is engaged and planning their nuptials for later this year. However, Tyler's doubts are apparent in the trailer, and he admits to his fiancée, "I don't know if I'm ready to be married…that's why we're here." Heavy stuff. To say they've been through a lot over the years is an understatement, but they're still young, and it's not a surprise they're still experiencing some growing pains.

+ Will you watch "Couples Therapy"? Check out the trailer, and tell us what you think of these MTV cast members being part of the show.

Get More:

Couples Therapy

Dig Remote Control? Follow us on Twitter, like, now.

Photos: VH1