It's followed near immediately by Mood Whiplash, but Benedick and Beatrice finally admitting they love each other and Benedick's heartfelt "Come! Bid me do anything for thee." That is love.
"I do love nothing in the world so well as you: is not that strange?" Sweetest declaration of love ever.
And Benedick swearing he will challenge Claudio, all because Beatrice asks him to, even though neither of them have any proof that Hero has been falsely accused. Recap: Benedick loves Beatrice so much he is willing to challenge his best friend on nothing more than her say-so, simply because he believes her that much. Catherine Tate and David Tennant in the 2011 production, especially, showed the whole damn world just how that scene is done.
Depending on the production, Beatrice's "let him down easy" moment with Pedro can be this, as she basically tells him he's too good for her. In Kenneth Brannagh's film version the scene is particularly sweet, coming across as just two old friends mutually deciding they're Better as Friends.
Benedick may have cracked a few jokes at Hero's expense at the beginning...but when she's falsely accused at the altar he believes and supports her pretty much from the start, when even her own father starts cursing her. When he challenges Claudio to a duel, he's not just doing it for Beatrice's sake but also because he's genuinely outraged at his friend's treatment of Hero.
From Nothing Much To Do
"All it takes is one little smile, one little acknowledgement that — that I mean something to you, and it's like everything just... stops." Damn, Ben. Just... damn.