'Does you boyfriend,' whilst at the very mildest of the homophobic abuse scale, quite clearly says there is something wrong with being gay or something incongruous with being gay and being at the football. The chant doesn't work without that insinuation.
Just one thing on the equating 'does your boyfriend?' to 'sheep-shagging' and 'inbred' abuse.
I find it very unlikely that there are many children at football matches who are becoming aware that they want to commit incest or bestiality. If they are, it's probably not a bad idea that they are...