I might've complained about this before, but whispered confessions not being heard. I hate it almost every time.
MC: "Why dont you find a guy you like?"
Girl, at nearly full volume: "What are you fucking talking about, idiot, I have loved you ever since our whatever plotpoint childhood promise only I remember, I love your face and attitude and family, and we accidentally kissed when I fell on the stairs and I love you so much."
MC: "What?"
Girl: "Nothing"
MC: "Aight, I'm not gonna press it, all those whispers I heard were probably nothing."
Honestly, I think the presented volume is the highest difficulty for me. If a girl mumbled, or if the guy pressed even a little, I'd allow a little belief, but it's just a beaten to death cliche.
Sometimes an anime will play with it though, and I can appreciate it. I remember "Haganai" makes him ignoring confessions part of an insecurity, and "So I Cant Play H" or whatever that dumb anime is has the MC purposefully ignore what we heard because he didnt want to turn her down and hurt their friendship.
Not great, but better than just leaving the cliche to exist in it's entirely formulaic format.