Second Male leads

You probably know where this is going hehe :P

What’s that one second male lead that you liked or even loved to end up with the MC but did not happen?

And, are there any second male leads who you DIDN'T want to end up with the MC?

For your answers i want you to describe their personalities, for example: if they have golden retriever personality, more mature, cooler etc..

It could be straight or BL :)