have known each other a long time
go back a long way
to leave home to live independently
fly the nest/flee the nest
free and without responsbility to anyone
footloose and fancy free
someone who is only there in your good times
fair weather friend
looks very much like
spitting image of
someone you used to have a relationship with in the past
old flame
not even born yet
twinkle in his father's eye
spend time with important or famous people
rub shoulders with
relatives
flesh and blood
did everything together
lived in each other's pockets