Facebook bigot problem?

i have this bigot on my pals list and everytime i post a picture of my kids in celtic tops to my album ...this person comes away with fenian kids ect ect real nasty stuff...and puts pics of its kids in similar poses to my kids only in rangers tops....if i delete it it will kno its got to me..i dont know what to type to its constant rundowns...i mean if it has a problem why not type it to me why about my kids? does anyone else have supposed chums like this? why the need to be a bigot on facebook?