get (one's) undivided attention
To do something to become the sole thing that someone is focused on. OK, now that your sister's asleep, you've got my undivided attention—tell me what happened earlier. You will get their undivided attention if you have your lawyer send them a letter.
get/have somebody’s undivided atˈtention
(often humorous) receive somebody’s full attention: I’ll just finish writing this sentence, and then you can have my undivided attention.