"Teen Mom OG" star Farrah Abraham explained her motives for joining the reality show in a recent interview, and revealed that she initially wasn't part of the cast.

The MTV show stars original "16 and Pregnant" castmembers Maci Bookout, Amber Portwood, Catelynn Lowell, and Abraham, but Farrah was added after filming had already begun.

"When I got the call to come back, it was a little bit awkward for me, and I tried to work with them the best that I could," Abraham told US Weekly. "I was just a little bit reluctant because of the progress I'd made while I was not on the show."

After leaving "16 and Pregnant" and "Teen Mom," Abraham entered the adult entertainment industry as a performer, purveyor of adult toys, and author of erotic novels. Her addition to "Teen Mom OG" was met with apprehension from some of her castmates.

"I'm not going to lie and say I was happy about it," Bookout admitted. "But, I mean, it's something that I guess people will just have to watch on the show. And it has nothing to personally do with Farrah at all. I have no hard feelings toward her whatsoever."

Lowell also had some concerns about the message of the teen-targeted show.

"At first, for a little bit, we were kind of OK with it," she told E! News earlier this month. "Until we really sat down about it and were like 'Um, we don't know how good this is for the moral compass of the show?'

"Like, we are trying to educate girls about good things, not so much the sex industry part."

Portwood took a more neutral stance.

"It's just shocking sometimes, to me, when I knew Farrah... she would never do something like [adult films], and when I found out she did, I was in prison," she explained. "I can't really judge much on anything."

Abraham clarified that her reasons for returning to reality TV are her six-year-old daughter, and the fans who will watch her each week.

"It's good to be back for Sophia's sake and showing how our lives are to help others," she insisted. "And that's why we're back."

Abraham has generally shrugged off criticisms about her lifestyle and in addition to her adult entertainment endeavours, has, contrary to expectations, appeared in Christian films and written a Christian parenting book.  

"Teen Mom OG" premieres on March 23 at 10 p.m. ET on MTV.