Okay here it goes. I am a sucker for Drama and this situation just drew me in. I guess you could blame Shelby for not realizing something was going on sooner but hey she is just a human. So this is my take on how she stumbles around in her mind in episodes 2x18 to 2x20 (in the end). Will probably be short. Italics is more or less directly from the show. (Which I sadly have no rights to)

Clay is struggling because of work ... That thing that is happening between you two. You've got to stop or so help me god, I will make your life a living hell!

"Caleb is ridiculous, right? Yes, Clay and I have become more friendly with each other but that is to be expected, work together for crying out loud."

Shelby is in her and Alex's room and trying to decipher her own feelings. Is there something going on between her and Clay or is it only in Caleb's mind? In the end she comes to a half conclusion:

"Pacing around is not helping! How in hell did I manage to land in this stupid situation again? Caleb is an idiot. There is nothing going on. And now I have to get some rest before I have to get up and in the damn van with Clay. (Caleb is going to love that, when he finds out.)"

Shelby is battling against sleep the whole time in the van and sometime around 4 am she drifts off to a dreamless slumber.

"Please, turn off the alarm."

Yes?... See you back at the farm.

"Crap. I have fallen asleep?! How am I getting out of this again?"

I am the worst agent ever...

When Clay hands her the coffee and fills her in she is more or less back at ease for a second. "He knows my coffee order. But that doesn't mean a thing, Ryan knows my coffee order."

I can think of worse ways to spend time than watching you snore.

"What did he just say? Is that flirting? No way, that is not possible. He is engaged. I am projecting and I am in need of a good girl talk back at the farm."

The way back to the farm is spent with friendly conversation and Clay even tells her some teenage stories about Caleb. The boy band thing sound hilarious and she is laughing just until she sees Caleb's warning look.

You know that word? Goodbye ... It's that thing that you can't seem to say to them either.