go back a long way
Verb
Meaning
go back a long way (third-person singular simple present goes back a long way, present participle going back a long way, simple past went back a long way, past participle gone back a long way)
To have known each other for a long time.
Synonym: go way back
Examples
You got to say hi to me. We go back a long way. She was twelve; I was thirty. But anyway this woman helped me get an awful lot done.