'Selling the OC' Sean Palmieri Fires Back at Ex-Castmates, Villain Label

Former "Selling the OC" star Sean Palmieri's going scorched earth on his ex-colleagues ... firing off a barrage of critiques -- and, telling fans who think he's the villain to look at everyone else's behavior.

We caught up with Palmieri on Rodeo Drive in Bev Hills and asked him about all the drama from this new season of 'StOC' ... including his own claim his costar Austin Victoria and his wife tried to have a threesome with him ... and, Sean didn't hold back.

While Sean doesn't hit the three-way question head-on, he does call out Austin for trying to hog attention and stir up drama around the office ... saying his adversary wanted to make him the villain.

As for that villain label ... Palmieri throws a slew of insults at his colleagues that ya gotta hear to believe. Check out the clip -- he's calling out Austin, Tyler Stanaland, Kayla Cardona and Polly Brindle here for their actions on the show.

SP ends his talk with us by claiming he's got the truth on his side ... adding speaking facts doesn't make him the villain.

It's a fierce response from Palmieri whose ex-costars have thrown out their own battery of claims ... like Victoria who said Sean was a toxic presence, and claimed people didn't want to work with or around Sean at the office.

Jason Oppenheim recently revealed Sean came to him and asked to leave the agency ... making it clear Palmieri was not fired.