y shouldnt u talk 2 someone who is sleep talking?

Answer 1

You might wake them up and that might irritate them if they were having a pleasant dream or get them irritated at you. My father used to talk in his sleep almost every night and my mother had to awaken him in order to get him stopped so she could sleep. He seldom remembered such talking when he awakened.

Answer 2

You should just have a little respect for other people, that's why.