Monday night, following "Teen Mom OG" Season 5 Episode 5 "Surprise Surprise," Farrah Abraham launched a Twitter attack against Gary Shirley, targeting his size.

Apparently, the former adult film star was unaware during filming of the episode that Gary had asked ex-girlfriend and mother of his daughter Amber Portwood if she missed a certain part of his anatomy. She heard it while watching the show on Monday night and took to Twitter to confront Gary.

"#LMAO [Gary Shirley] can you even see your p*nis anymore? Is That Really Your baby #TeenMomOG @mtv #GaryTheHairyFairy @AmberLPortwood," she said. 

Amber, who had seen her "Teen Mom OG" co-star's tweet, weighed in.

"Omg farrah lol the gauntlet is thrown haha@F1abraham @ItsGaryTime @MTV," Amber tweeted.

Gary got in on the action and offered a witty response to Farrah's not-so-nice message.

"Dear @F1abraham yes I can see it! Just as well as everyone can see your money maker!" Gary wrote on Twitter.

It was rather surprising that Amber responded with amusement to Farrah's tweet considering the two have had issues in the past. Also, Farrah's return Monday night didn't impress her co-stars; she got upset with show producers and was unwilling to do anything they asked. Plus, she was angry at her parents.

Amber revealed her feelings toward Farrah in a recent interview with MTV for the After Show, via Wetpaint Entertainment.

"Honestly, I feel two ways about Farrah. I see her when she's rude, and then I see her when she's crying and she's actually hurt because she was rejected in the beginning. She had every single right to feel that way. But then again, it's how you come across when you talk about it and with your classmates, and burning bridges with everybody," Amber said.

In Monday's episode, "Surprise Surprise," it became clear that Gary likes to play mind games with Amber and his current girlfriend, Kristina Anderson. Not only has he been flirting with Amber, but he told Kristina that he isn't sure if he and Amber will ever be together or not -- and Kristina is pregnant with their first child.

Check back later this week for "Teem Mom OG" Season 5 Episode 6 spoilers. There's no doubt the drama between Gary, Amber and Kristina will continue.

Watch "Teen Mom OG" every Monday night at 10 p.m. on MTV.