Say you hate being called a specific nickname or pet name, but there’s one person who calls you it and you secretly like it? I’ve tried finding a word, but I don’t know if there is one. Maybe there’s a phrase?
One expression is to have a soft spot for someone. Farlex has
a soft spot
A particular fondness or affection for someone or something, often for reasons that [are] hard to understand or articulate.
So you could say:
I hate being called diddykins but secretly like it when X calls me that. I have a soft spot for her/him.