Nobody should be allowed to call himself a fan Keith - until he's proved himself worthy, and bought you a drink. Then he can call himself anything - a friend for life, a fan, member of the family, a one night stand.....anything.

As this person seems keen on the protestant cause, I think he should prove his committment by buying you a bottle of Jamesons.

Brendan Behan used to call it 'the protestant whisky'. However it can be acceptable in non-denominational, and multi-faith settings.