Raj always thought he liked girls. His hockey buddies liked girls, Wayne liked girls, it just seemed natural to be into girls but then he went to Total Drama Island and met Bowie. The two immediately clicked when they first interacted. He expected Bowie to be turned away by the spillage on his clothing but it didn't even seem to faze him whatsoever. The more they interacted, the more they began flirting. Well… Bowie had been flirting, but Raj was always receptive to it.
Wayne had figured out Raj was gay after the events of Episode 4, but waited patiently for Raj to tell him by himself. Though Raj didn't pay much mind to that, he was still trying to figure out his feelings for Bowie. Eventually, Raj had impulsively kissed Bowie in the catapult challenge in a pool of pudding with pudding sharks. It's a lot more romantic than it sounded. Raj was so scared when he talked to Bowie again, afraid that he had offended Bowie in some way, but instead, he was receptive to the kiss and was willing to take things forward… after the competition of course.
Bowie never expected to find a boyfriend in Total Drama Island, he had also never intended to. He came for the crown and nothing else. That's why he booted Caleb first after all. However, once he started interacting with Raj, he started to bond with the hockey lover and grew an attraction to Raj due to how sweet he was. He couldn't bare to hurt Raj, so the second they confronted each other after the kiss, Bowie set the record straight that they are still in a competitive environment and that he would not be holding back in the inevitable situation he would have to sabotage Raj's chances of winning so he put their growing relationship on pause until the game ends. He saw the first three seasons, he did not want another Duncney or Gwent situation.
Once the competition was over, Bowie and Raj became inseparable. Not to the point where they were codependent but they learned to rely on each other as the years went on, and despite the few disagreements they shared, they never broke up. Bowie learned when to open up with him now having to consider the feelings of his significant other and Raj learned to be less reckless in his endeavors(especially after getting a LONG lecture from Bowie about his prank on Keith). Either way, Bowie and Raj both knew their relationship was meant to last, that's why Raj had immediately kissed Bowie when he had proposed.
And here they were now on their wedding day. The entirety of their cast was invited, even Julia and Ripper couldn't help but show up for the ceremony. At the wedding, Bowie gives Raj a reassuring gaze to let him know he can always trust him, and Raj believed it wholeheartedly. They kissed with no hesitation and playfully shoved cake in each others' faces at the reception and Wayne couldn't be more proud. Bowie and Raj are happy together nowadays because they know they can feel comfortable around each other and rely on each other to help one another when they crumble. And as Bowie thought his whole life, Happily Ever After doesn't have to be hetero.
Author's Note: So I'll pretty much be doing canon couples with a pinch of fanon to spice things up. Give me your requests but I want actual feedback on this.