Erm, wave at them?

I say hello, once they are an ex,unless they commited acts of physical violence or caused you some kind of ptsd, then an ex is just that. Someone you shared a portion of your life with and moved on. Too many people carry secret feelings about their exes creating a stigma that makes it all weird.

just say hey and ask how they are, be the bigger person and don’t cower

Curb stomp him

I don’t have ex

Just keep walking

nothing, keep it pushing

nothing mind my business

Speak and keep it moving