The 38-year-old Williams, who has often landed in trouble because of his outspoken nature, took pot shots at Jessie on a Dutch TV show, the Daily Mail reported.
"She's not gonna last for very long, though, is she?' Continuing he added: 'She's great, Jessie. I give her 18 months," Williams said.
The 'Angels' singer then went on to strip to show his Celtic Cross tattoo which is located on his thigh.
It is not for the first time that Williams has hit out at Jessie's career as he once said that he did not like 'The Voice' fronted by Jessie J.
"I don't watch it. Sometimes it's very difficult to go on the emotional journey with the contestants. I'm exhausted with how many times I'm to go on the emotional journey with this person who had a hard luck story and then da, da, da, da, blah, blah.
"I'm sure I'd be a good judge but no, I've got a career," he had said.
