Supporting is a strong word... i support Liverpool FC, my home club who i adore.
I have purchased merchandise and spent ridclious amounts on watching them since i was old enough to go, thats supporting your club.
I wouldn't even say i follow any other teams, i like to watch Barca, i like to see Blackpool do well this year apart from against us, Arsenal play an attractive brand of football that i will happily watch if there on tv, and then there's teams that i don't have a particular dislike too, newcastle..west ham etc. I don't like to see Everton struggle either, there the 2nd club in the city and represent it.
But i would never say i support 2 clubs... one love LFC