Wht did he mean by the day he didn't pick him up??? What happened that day?

I think Mc and his Hyung went to the prostitution parlor for a mafia deal time ago, they might have engaged in the service (since we see the flashback of them in the bath) and then I hypothesise something happened with the deal and they crushed the parlor owners and left all the young guys who were there to fend for themselves, hence why “he didn’t pick him up” but its just my understanding (●'◡'●)ﾉ