When I meet people for coffee, lunch or whatever. My policy is phone face down and on vibrate. Only if it's an emergency do you pickup and answer.
I tell people respect my time, it's pretty valuable. If you want to occupy your space with someone, at least have the decency to be there at that moment.
Anyone fails to do that, I simply do not spend my time with them. You soon get to find out, who not only respects your time and values theirs. Verses people who don't do both.