Rex, now 43, had appeared in several adult films prior to his 2004 date with Markle, and has even claimed to have won an award for Best Gay Solo Video in 1997.
He is now also a comedian and rapper, using the rap name Dirt Nasty.
Reports say Markle and Rex had their one-off date in Los Angeles after meeting on the set of short-lived US sitcom Cuts, when they both guest-starred in the same episode.
In 2014, Rex admitted to appearing in adult films, saying: 'I went there and did that sh*t. It was just enough to pay the rent at the time. I was living in the moment. In hindsight it wasn’t the best move.'
It's unknown if Meghan knew about Rex's acting past.