i could definitely see some variation of this happening. i feel like it would go more along the lines of billy and steve (or at the very least steve because billys a harder nut to crack) start opening up to each other when theyre alone and theyve become more intimate, more vulnerable around each other. talking about things they wouldnt share with anyone else. and then one day, whether it be after practice or just somewhere at school, billy and tommy are doing their usual ragging on steve and steves had enough. he knows that this is billys way of covering his ass but he’s just so done so he starts retaliating and standing up for himself. things escalate and eventually billys throwing out things steve has said to him in private and using them against him. billy can tell by the look on steves face that he crossed a line, if the low “fuck you” wasnt already doing it. for a split second billys face falls because he’s terrified he just ruined everything but its not like he can run after steve right now and apologize so he just stays back and continues to play the role of worlds biggest dickhead.
steve wont talk to him for weeks after, they have a huge fight. its real bad
when you spend your days thinking about possible headcanons for s3 Billy/Harringrove but then suddenly realise that the likelihood of any of it becoming reality is slim to none and that Billy is probably going to sleep with a middle aged housewife n then he’s also, more than likely, gonna die without any exploration of his characters issues or back story and ultimately will just be a dead-end character that had no real purpose or meaning