Amber Portwood: What Allegedly Led to 'Teen Mom OG' Star's Fight With Andrew Glennon Ahead of Arrest

After Teen Mom OG star Amber Portwood was arrested on felony domestic battery charges in relation to a fight with boyfriend Andrew Glennon, a source close to the couple is speaking out about the complicated situation surrounding their relationship ahead of the altercation in a new interview with Us Weekly.

While initial reports indicated that the fight first began over a July 4th celebration gone south, the source indicated that Portwood's anger may have been simmering before then.

"She wasn't just upset out of nowhere," they explained. "There were things going on between her and Andrew that led to this."

Portwood and Glennon, who share 1-year-old son James, first got together shortly after the MTV personality called things off with ex Matt Baier, whom she has accused of stealing money from her and being abusive. Glennon, she had hoped, would be a change of pace, and things were going well between the two as they navigated life in a blended family. (Portwood also shares 10-year-old daughter Leah with ex Gary Shirley).

"For the most part, it has been good, but lately a few issues have popped up that have made her question things and challenge her trust in him," the insider added to Us. "She has been through a lot. She just wants to be able to trust someone, and there have been major issues."

Being open about her struggle with bipolar disorder and mental illness amid past arrests for substance abuse and domestic violence, Portwood reportedly also "feels pressure" to show personal growth from her past struggles. After this incident, the insider confessed she "hates that people will think she hasn't."

The reality personality's relationship with Glennon might appear to be in flux at the moment, as Glennon seeks full custody of their son, but the insider insisted things aren't over between the two: "Amber and Andrew still really care about each other and this is not the end of their relationship."

Teen Mom OG airs Mondays at 9 p.m. ET on MTV.

Photo credit: Jon Kopaloff/FilmMagic