The actor had dated a string of adult performers in the past and is currently with blonde star Brett Rossi.

Charlie used the romantic Valentine’s Day weekend to pop the question and confirmed the good news to People magazine in his usual quirky fashion.

"With all due respect to Donna – that maiden Klay-Vinn was annulled. Therefore, if "three" truly is a charm; The mashup/acronym of the real CS, (Charlie & Scottie) HAS to be; "Char-M-stee..." xox c&s, (sic),” he said, referring to Brett by his nickname for her, Scottie.

It will be the 48-year-old’s fourth marriage.

Charlie wed Donna Peele in 1995, but they divorced a year later.

In 2002 he married actress Denise Richards, who he has two children with, Sam and Lola.

Denise filed for divorce in 2005, after which Charlie began a relationship with Brooke Mueller.

They wed in 2008 and have twins Bob and Max together, but finalised their divorce in 2011, among a highly publicised custody war.

Brett seems over the moon about the engagement and opened up about the proposal to E!.

"Yes! We are engaged! He even was a gentleman and got down on one knee," she grinned. "I was not expecting it at all. We had a beautiful Valentine's day and he proposed to me early this morning after we watched the sun rise.

"The ring is classic and beautiful, but I don't have any photos to share just yet. This is the happiest moment of both our lives. He's my best friend and my soulmate."