Warning: SPOILERS for Sex Education season 3.
When Rahim almost gets in trouble for the flying poo in Sex Education season 3, Adam surprisingly speaks up and takes the blame. The two previously seemed quite at odds since they were both vying for Eric’s affections in season 2, with Eric ultimately choosing Adam over Rahim. But in Sex Education season 3, Adam and Rahim seem to put their old feud aside and develop a kind of friendship, which all starts when Adam takes responsibility from the bus poo incident.
There’s no overt reason why Adam would speak up on Rahim’s behalf at that point in the story. He attempts to reconcile with Rahim on the trip, but he’s rebuffed, as the other boy clearly still holds a grudge against him for “stealing” Eric. Adam and Eric later break up, but they’re still together by the time of the poo incident. So why would Adam voluntarily put himself at risk, all for someone who’s only ever been cold to him?
One possible explanation is simply that Adam is actively trying to be a better, more sensitive person in Sex Education season 3. He wants to atone for the less than admirable ways he’s behaved in the past, and he clearly doesn’t want Rahim to think he’s a bad person. Standing up for him and taking the blame for the poo incident is a powerful way to show support and mend the damage between them, so it makes some sense for him to jump at the chance given the guilt he feels.
It’s also worth noting that Adam is relatively used to getting in trouble. One of his major arcs in Sex Education season 3 is accepting that he can be good at things, and that he’s not just a screwup. He’s still aware of his reputation, however – a reputation that wouldn’t be made much worse by taking the blame for the poo incident on the bus. By contrast, if Rahim was exposed as the true culprit, it could have been devastating for his image. That could have played a part in Adam deciding to speak up.
Lastly, it’s possible that Adam has some unspoken feelings for Rahim that could have subtly motivated him. It’s unlikely that any attraction was conscious at the time of the poo incident, as he was still with Eric at the time and clearly cared for him very much. But by the end of the season, it’s implied that something more could be blossoming between Adam and Rahim. It should be interesting to see how their relationship develops in Sex Education season 4.