'Did you see that iconic photo I took yesterday of my patented gourmet beans on toast recipe?'
'Fuck that shit, I wouldn't join your Instafam if you payed me bruv'
'Finally reached 20,000 followers, bigluv to all my Instafam!'
When a person marries someone who already has children from a previous relationship, usually said of a single, never married man. Single, never married men tend to use this term in a derogatory manner until it happens to them.
This may be considered an alternate definition of 'instafamily' as well.
Bob's new wife has three kids from her first marriage. Bob has an instafam- just adddaddy.