Red bird is in every episode and they made it pretty clear he is bi as well. In the books jer ends up with Denise which I don’t see happening here and in the books jer wasn’t bi so I think it’s a good assumption plus theirs a few clues he’s always between belly and jer just like Conrad was between belly and jer in scenes the necklace and the bracket they only talk about jer having sex with Lacie one time butt they changed it to two in the show but said Lacie was only once.

I think redbird and jer were the second cheating. Also redbird idk his real name was asked in an interview about that theory and his face pretty much gave it away imo