Throughout the game, you are able to call people and ask them to “Hang Out”. You can then take them out to either a bar, movies, stripclub, etc.
I know in Grand Theft Auto 4, there were perks given to the player that completely developed a friendship with someone.
Is there any reason to “hang out” with people in Grand Theft Auto 5?
As far as I know, this has been (together with the romance part) removed from the game.
Hanging out with your friends is just a way to do the ‘pastime activities’ which also count towards your 100% checklist. But they can also be done alone.
And it’s a way to get some more back-story through the dialogue.
(Of course you standard perks train while hanging out, e.g. stamina when running, etc.)
Source : Link , Question Author : Dom , Answer Author : Chaos_99