"Teen Mom OG" fans met Amber Portwood's secret boyfriend, Matt Baier, on Episode 6, which aired on April 27.

On Monday's Episode 7, the couple will take their relationship to the next level. Matt, 43, proposes to Amber, 24, as they enjoy lunch at the restaurant where they had their first date.

"I love you, you know that, right?" Matt said in the sneak peek clip. "We've done a lot of messed up s**t in our life. Would you agree with that? I would really, really, really like to do something right for once. And I want you to marry me."

Amber's expression in the clip is of utter disbelief. She looks so surprised that Matt is prompted to say, "I'm being 100 percent serious." He then presents a diamond engagement ring and asked, "So will you marry me?"

The marriage proposal comes just six months after Amber started communicating with the Boston native. They hid their relationship from the "Teen Mom OG" producers. When Amber and Matt met in person, their chemistry and relationship was validated. They could not deny their love or hide it any longer.

"The relationship me and my fiancé have right now is completely different than what mine and Gary's was," Leah's mother told MTV during a recent interview.

Matt seems to be a stable, mature guy who can give Amber the support she needs. When Amber received a text message from Gary Shirley, 29, that upset her, she asked to meet with him to discuss it.

"To see my fiancé sitting there, being mature, taking control and calling him out actually and saying, you know, 'I don't like you calling her a bitch' and things like that -- I don't have other people that see that stuff," Amber said.

Fans are not thrilled about Amber's new man, reports Radar Online. The 19-year age difference and Matt's criminal record have fans quite concerned. Matt is a recovering addict, plus he has been arrested for issuing checks without funds, simple assault and driving under the influence.

Meanwhile, Maci Bookout, 23, still struggles with Farrah Abraham's return to the show.

Last episode, she said that she would quit the show after the series' executive producer Morgan informed her that Farrah was being reinstated to the cast.

"I had a lot of things running through my mind when Morgan told me that Farrah was coming back to the show," Maci told MTV. "When I was approached about the show coming back on, I made it very, very clear that I was not going to have any part of [it] if her story was going to be on the show too."

Maci said her reaction had nothing to do with Farrah, 23, personally.

"I just don't find it appropriate to put my 6-year-old son on TV where one second we are at the baseball field playing baseball and we come back from a commercial break and now we're at a strip club. That is not appropriate. If it was, 6-year-olds would be able to get inside strip clubs," she said.

Catelynn Lowell, 23, and Tyler Baltierra, 23, who have been together since the 7th grade, are awaiting the arrival of baby Nova. Catelynn, who has struggled with health and weight issues throughout her second pregnancy, was diagnosed with Gestational Diabetes last episode. She is very concerned how that will affect Nova.

"[Nova] could be like a 10 pounder, and it could lead to childhood obesity," Catelynn said.

The mother-to-be's health and that of baby Nova will be explored on Monday's all-new episode.

Do you agree with Maci that Farrah's storyline is too adult for the show? How do you feel about Amber's whirlwind romance and engagement? Share your thoughts in the comment section below.

Watch "Teen Mom OG" Monday, May 4, at 10 p.m. ET on MTV.