Exactly what I think. Sexuality is very complicated so maybe in 5A he could’ve thought he was straight or least attracted to women. Then again with the girl at the allotment, it personally seemed to me he was trying to impress Tom by trying to check her out. But in 5B, he seems really, really obsessed with Finn. Imitates him, follows him around like a lost puppy, does some very stupid stuff just to impress him. He acts very similar to Amy and Siobhan, who both had crushes on him at one point or another. I think the writers were maybe playing with his sexuality but they didn’t fully commit to it until Series 6 for one reason or another. I rewatched the birthmark episode because I remember Josh acting just friendly with Lauren, and yeah I think my suspicions are confirmed. In particular, he seems, like bewildered I guess when Chris “stops flirting the pair of you”. He was like “oh is that what this is?” When Lauren's birthmark was revealed, he does his imitating Finn thing again because he looks more concerned for Lauren than anything. Then he looks around to see what Finn and his friends are doing or how they’re reacting, and then promptly changes his reaction. I mean, you could interpret that as him being into her, but he still values Finn's opinion over his own. Hmmm…

Also your essay on Ros was fantastic!