I'm not sure. It doesn't make a whole lot of sense for it to be real -- we have seen literally no reason for Floki to go from "I love Ragnar, let me open my home to him, even though doing so could cost me" to "I hate Ragnar let's kill Bjorn to hurt him!"

But I can't really see what he'd gain from faking a betrayal. Everyone already knows that Horik isn't happy with the way Ragnar (and now Lagertha) is doing things, so it's not like he's getting new information. I guess they could try and set Horik up so that Ragnar could kill him, but I feel like there are better ways to go about that.

A lot of people speculate that Floki is acting as a spy for Ragnar to find out what Horik's true plans are. It's obvious that Horik wants to bring Ragnar down, they just don't know how yet.

Thank heavens, he was loyal to the Lothrbok family!!!

I will answer this with what I was thinking when I watched that season. Floki was showing signs of distrust on Ragnar. He hated Athelstan, blamed him for everything. Was anger at Ragnar, criticizing him. So yes, I actually did believe Floki was going behind his back. Was epic when he wasn't.

idk