In an alternate universe [2012 Tmnt] where everything is the same EXCEPT Donatello and April get together at some point near the end of the show...
Raph doesn't pull his verbal punches towards Donnie, and it's more likely than not that he still has some teasing remarks to pit against him even after the two establish and make their relationship known to everyone else.
But it's a different story when he and April find themselves alone together for the first time since, and he has some choice words to say. Something along the lines of:
"He’s a good guy, smart and everything, but he can be naive. I’ll know if you’re taking advantage of him."
"I've seen his heart break before. Just be careful with it."
"If you think you're what Donnie deserves, you're gonna have to prove it. Every day."
[Insert more Raph-isms because I could probably go on forever]
It's not like April wasn't already a part of the family, and he does care about her, but he's seen how the redhead has taken Donnie's heart for a joyride in the past. Unintentional or not, it's not something he can ignore. Despite how Raphael gives him a hard time, at his core, he's a protective big brother, and he won't accept or allow anything less than what his family deserves: to be happy.














