It really isn't a big thing, they (the alleged Arsenal fans) probably thought they were being hilarious, is that so unusual of football fans?
I've heard Brighton fans singing England songs, when England weren't playing :shrug:
By stating they weren't kids are you saying they weren't students then? You should be more concerned about the fact that 8-10 adults were able to buy student tickets, which is indefensible.
As for happy with it, I don’t really care, there were 600 odd fans at the other end who occasionally sung...
Can't help but think there is an agenda here.
Student football fans go to watch local football wherever they find themselves studying, it's far from a unique situation at Brighton. I wonder what the OPs problem is with this quite normal state of affairs in a University area?