Although my main support is for Andy, I'm a fan of a few other tennis players because I enjoy watching the sport, so I don't see anything wrong with that.
For me the 2 sports are completely different. I'm a Nadal fan as well but I'm always 100% for Andy if they meet. I enjoy watching other players but I think that's very different to giving yourself the label of a 'fan'. For me at least.
I think with football you have your home town club and perhaps a foreign club. I have my home town and FC Barca. No conflict as they will never meet. I enjoy watching other teams but 2 is my limit for football. Andy seems to change from week to week. Nadal is just as weird. His logic when it comes to his team(s) in La Liga is just bizarre.
To be honest Andy's just bugging me with his tweets right now. I better never see him in a Barca hat again. Pretty obvious why his tweets are annoying me..haha.