LONDON: Paris Hilton's boyfriend's mother has started referring to her as ''daughter-in-law'', while they holidayed together in the Caribbean.

Paris Hilton is referred to as "daughter-in-law" by her boyfriend's parents.

Doug Reinhardt and the hotel heiress recently spend a week with his mother, Kelly and stepfather Duane Roberts at a luxury villa on the Caribbean island of Anguilla, fuelling rumours they will soon marry

A source told website X17online: "Paris and Doug looked like they were on a honeymoon. They would be on the beach for hours, just staring into each other's eyes, kissing and laughing.

"At dinner Doug's mom was overheard referring to Paris as her, 'daughter-in-law' and it's pretty clear that Paris' family feels the same way about Doug."

While enjoying the break the couple reportedly went scuba diving through local ship wrecks as well as enjoying the facilities of the estate, including a private swimming pool, tennis court, fitness centre and cinema.

Paris, 29, has previously talked of the possibility of her and Doug, 24, marrying this year.

She said: "I wouldn't rule out a wedding in 2010. With how amazing everything is going between us, I see a very bright and happy future."

After a night out in February with Doug and her parents, Paris tweeted about how pleased she was at how well they got on.

She wrote: "What a fun night! My mom and Doug were so cute dancing together! I love how my parents love my love! We all had a blast! Great night! (sic)."