Fifty Shades of Grey author EL James has left Piers Morgan red-faced on Twitter after the British broadcaster was humiliated in front of millions by JK Rowling last weekend.

Morgan engaged in a Twitter feud with the Harry Potter author after she praised Australian comic Jim Jefferies for telling Donald trump supporter Morgan to “f*ck off” on US talk show Real Time with Bill Maher.

Following the high-profile back and forth, Morgan has since been trolled by many including an account who is sending the entire Harry Potter book transcript to him line by line in tweet form (that's 32,567 tweets).

Morgan has now embroiled James asking her if she'd mind tweeting him one of her books stating he “needed a break” from the Harry Potter bombardment.

James' reply has left the majority of Twitter users fist-pumping the air in delight - she replied with a line from what he would have assumed to be one of her Fifty Shades novels.

In a follow-up tweet, however, she revealed it was a quote spoken by self-promoting slimeball Gilderoy Lockhart, a character in Rowling's Harry Potter series.