Ryan tries to keep any hurt feelings to himself and rarely shows a sensitive side (not counting the incident when he cried at a reunion with Dr. Drew). But during this week's Teen Mom OG episode, Maci's ex could not help but tear up at a Father's Day gathering.

So what unfolded with Ryan, who had recently returned to Tennessee after seeking treatment? Bentley saw Ryan for the first time since rehab on the holiday at Jen and Larry's home (the afternoon visit was not captured on-camera). After Maci and Bentley left, Ryan expressed his frustration to his wife Mackenzie and Larry about what had just unfolded. While Larry believed that Maci was still in love with his son, a visibly peeved Ryan outlined the next steps to be able to be with Bentley (first mediation and then if that doesn't pan out, an imminent court visit). And that's when Larry had some thoughts about his boy's situation (a snippet of the conversation can be seen below).

"I'm not afraid," the MTV grandfather firmly stated in t. "I'll tell it like it is -- it's not going to change a damn thing no matter what I say." Then, looking straight at the camera crew, he continued, "I'll tell you one goddamn thing: One day, y'all are going to know the damn truth. And so will Bentley."

Something obviously struck a chord with Ryan, who began to bite his nails as his eyes turned watery.

"What's wrong?" Mackenzie asked her husband. But Ryan kept quiet and just shook his head, trying to keep in the tears.

It's not a familiar sight to see Ryan upset, and time will only tell what sparked this emotional reaction. But what do you think caused it? And can Ryan and Maci be able to reach a co-parenting agreement, or is legal showdown just around the corner? Keep watching Teen Mom OG every Monday at 9/8c.