Rumer Willis couldn't stop laughing when she heard her mom Demi Moore's lisp from losing her two front teeth.

The 28-year-old beauty reportedly burst out into tears of laughter when she phoned the 54-year-old actress after she ''sheared off'' her gnashers due to stress and found it even more hilarious when she spoke strangely during their call.

A source told the New York Post's Page Six Column: ''She called her to check in and see what happened, and was trying not to laugh over the phone because her mom sounded like a kid with a lisp after losing their two front teeth.''

The 'Ghost' star hinted she had ground her pearly whites down during an appearance on 'The Tonight Show Starring Jimmy Fallon' on Monday (12.06.17).

The 42-year-old talk show host quizzed the 'Rough Night' star on a photo she had sent in to the NBC show's studios, in which one tooth is visibly missing.

He said: ''You sent us a photo and it's the most insane thing I've ever seen. How did this happen?''

To which she replied: ''I sheared off my front teeth. I'd love to say it was skateboarding or something really kind of cool, but I think I think it's something that's important to share because I think it's literally, probably after heart disease, one of the biggest killers in in America, which is stress. Stress sheared off my front tooth. But, in an effort to get ready for you, I wanted to make sure my teeth were in.''

Demi said that her grown-up children, Rumer, 23-year-old Tallulah and 25-year-old Scout - whom she has with ex-husband Bruce Willis - think their mom is more ''fun'' and ''vulnerable'' looking without her front teeth.

She said: ''My children love seeing me without my teeth. They think it makes me look more vulnerable and fun. I literally knocked it out, it was almost like it fell out my warranty was up.''