I could be wrong about Kent saying he was waiting on a friend... but I do remember him saying something about waiting for his sister to arrive. Here are my notes from the Lordanarts vid:
~23.20 – Were you expecting him home that day? Not that particular day, he hadn’t told us yet. Sometimes you hang out with friends for a few days before coming home. (not exact quote). Both boys were waiting for the sister to come home before going to parents house.
No mention of when she was arriving by father. However, this tells me that until they knew she had arrived, they weren’t going to be there (MOO). Reminds me of parties where no one wants to be first and hang out with just the hosts, (or your parents in this case), so they are ‘fashionably late’.