To answer mck16's question on relevance:
I would think it would make sense that MR would want the shopping input from DR. It is not like they spent a great deal of time together and he wouldn't know what DR would necessarily like.
Understood and agreed. That's why I'd like to know if MR had any conversation with Dylan before his flight. You know, like " what would you like to have around the house to eat and drink while you're here, buddy? I'm sure looking forward to seeing you." And if not, what groceries did they get at Walmart after Dylan's arrival? What groceries were in the house? In other words, was there any appearance at all that MR was prepared to have a 13 year old son visiting for a week? If not groceries before arrival, or from Walmart after arrival, what groceries did he bring from that 45 minute drive back Monday morning?
Also, my understanding is that they had recently done a big fun trip together out of state. I would think, as a 'caring' parent, MR would have had plenty of opportunity to get to know what Dylan liked? It would be hard to NOT notice that.
But the key word here might be 'caring'. There are parents and then there are parents. Donating sperm is the easy part.