i'm experiencing crimson flower for the first time, was so flummoxed by Hubert expressing third wheel jealousy towards m!byleth over edelgard. Like what the hell are you saying hubert, your husband is obviously ferdinand
Hubert saw Ferdinand toting around coffee and not only assumed it wasn't for him-- the certified Coffee Drinkers of the army-- but also assumed it was for someone Ferdinand fancied-- again, not himself.
I think it's safe to say that Hubert is the last person to realize Ferdinand has romantic feelings for him. In fact it might be until Ferdinand is literally on bended knee in front of him that Hubert is like "Perhaps von Aegir... but no, I shant say it."
Enjoy Crimson Flower!!! Let me know other thoughts and feeling as you go :D