President Donald Trump has criticised musician John Legend for not playing a role in passing criminal justice reform following a TV special on the subject in which the star appeared.
Mr Trump also said he has not got enough credit for signing a law instituting some reforms.
The law reduced mandatory minimum sentences, among other measures.
In a series of tweets late Sunday and early Monday, Mr Trump called Legend “boring”.
He also said Legend’s wife model Chrissy Teigen as “filthy mouthed”.
Legend responded by saying Trump is hungry for praise and asked Trump’s wife Melania to step in.
Teigen wrote she did not appear on the special and used crude language to describe Mr Trump.
Donald Trump in Twitter feud with John Legend and Chrissy Teigen over justice reforms