Kanye West Fires Back At Ray-J Five Months After Controversial 'I Hit It First' Song

The question is why would a whole Kanye West take so long to reply the Ray J. While performing to one of his song (Bound 2) on Jimmy Fallon last night, Kanye changed the first line of the song and replaced it as

 "Brandy little sister lame and he know it now. When a real brother hold you down, you 'sposed to drown"

What took him this long before responding? After massive airplay of 'I Hit It First'