Watch What Happens Live With Andy Cohen went down a treat with viewers who tuned in on January 17. Famed interior designer Jeff Lewis and reality star Mercedes Javid joined Andy in the After Show where he asked them some all-important questions about their current lives. Shahs of Sunset star Mercedes ‘MJ’ Javid is doing all the things this year as she appears on Peacock’s The Traitors US and is now working at The Agency. During Watch What Happens Live, she tells Andy Cohen what it’s like having Mauricio Umansky as a boss and it seems she only has good things to say. MJ sings Mauricio Umansky’s…