Lunch?

[thecorpus]

you know, when you bump into someone you haven't met in a long time

could be an ex-colleague who you never had lunch with when you were colleagues
could be an acquaintance who you really have nothing to say to
could be an old friend who is well an old friend for a reason

and you exchange pleasantries

and either of you will suggest to meet and catch up proper

usually over lunch

which could mean

you would like to have lunch but this person is just not on your priority list
you wanted to end the awkward conversation politely
you wished you had made more of an effort and so you're trying to make things up

or you pretend you did not see him / her.

i hope i never bump into you.