We live near Blue Town. Ds (15) supports Red City FC but has never been to a premiership match. For Christmas we got ds and the whole family tickets to see the match between Blue Town and Red City when the reds play here.
Ds is insistent that he will wear his Red City scarf and cheer loudly for the reds despite us being seated right in the middle of the Blue Town stands. He thinks because he's only 15 and cute the blue fans won't mind. 
I haven't been to a match since 1986 for a while, so have no idea what to expect. Will we actually get out with all our limbs intact if ds does this? Should I ban him from wearing anything red or is football now family-friendly entertainment where the home crowd ruffle the young lad's head and congratulate him when his team thrash the home team?
(For context Blue Town is fairly well known as 'rough' and there were no options to get tickets in family friendly seats.)
Tips, advice and sneering derision constructive comment welcome. 