I said (not on this blog) that the new gen protagonist and rival pair is gayer than the first gen pair. I was wrong. I just caught up on the many manga adaptations and I can say that cross-canon wise, the first gen pair is still gayer than any gen that comes later. In at least 3 different adaptations, Red/Ash and Green/Gary end up living and/or travelling together. If Ash was heterosexual, why would he dump Misty and Brock to travel with Gary [Electric Tales of Pikachu]? Ok, in that version Ash and Gary are much closer than their counterparts and have a healthier relationship, but still, Misty! At least take Misty with you! Ok, maybe she spent all her trainer's leave and has to go back to school now, but do remember to bringer her to adventures when she graduates please? Ok, travelling with Gary alone must be fun since the two kind of have a proto Crowley-and-Aziraphale kind of relationship, but still, Misty... And it's in the same chapter where James and Jessie got married and Jessie ended up pregnant. Do we have a Crowley-and-Aziraphale/Fire Emblem type shiptease here? Like, that the couple have a together ending in an epilogue where all others have a confirmed marriage + children ever after ends, but never specify if the together end means that they are a romantic couple and they don't have children ever after because of biological limits or they just happen to be geographically and spiritually together so their ends are one together end. Just like the Raven + Lucius one. Or Lyn + Fiona. Or Crowley + Aziraphale (they were going to live together in a cottage too!).
Oh, and don't give me the "they're just ten!" excuse. In at least two of the Red(Ash)/Green(Gary) case there's a flash forward and they should be something like 16+.
Gen I male!protag and rival team, you win. No pair so far is heavier in homoerotic shiptease.
But still, Ash/Red x Misty does have a fair share of shiptease. And Ruby/Brendan x Sapphire/May (Gen III original Schrodinger protagonist and pseudo-rival) too. Not to mention Lyra x Silver/Sou/Rival (Radio Tower stripping scene and tag battle at Dragon's Den, anyone?) or Silver x Ethan (same reasons, as Ethan and Lyra are Schrodinger protagonist and friend again). Also Barry x Dawn (Gen IV original, Lucas and Dawn are Schrodinger again, but the relationship with rival Barry only looks romantic if Dawn was picked despite having the same dialogues... to me, at least).
Conclusion: The heaviest shiptease regardless of orientation is Brendan x May in my opinion. Wait, no, It's more like Eusine --> Suicune, but that one is unidirectional so it doesn't count. The gayest, however, is still and probably always will be Gen I boys pair. I can't believe that they beat Silver/Sou/Rival x Ethan even if Sou pretty much stripped Ethan in public and probably held his hand when tag battle against Lance and Clair. Sou x Ethan could beat the Gen I pair if Game Freak makes a sequel where they are living together or running a day care together, but that likely won't happen (if it happens it should and better be Lyra, Ethan and Silver all work in the same day care or Lyra and Silver live together with Ethan as neighbour). And even if N (antagonist + rival) and Blair/Hilbert/Touya had a ferris wheel ride together, it's not yet canon that it was Hilbert on that ride as Hilbert and Hilda are Schrodinger protagonists and fanon wants the one on the ride with N to be Hilda/Touko.
Ok, sorry for doing pokemon babble again. I didn't expect to land on Nuzlocke page while surfing randomly on TV Tropes. It awoke my pokemon soul again.
P.S.: The spelon berry tree in Gen II games is adorable! It looks like an angel! How does a berry so ugly have such a pretty tree?