Robert Pattinson is ''in heaven'' with FKA Twigs.

The 'Remember Me' actor - who has been dating the 26-year-old for three months - is reportedly really enjoying the intimate side of the couple's relationship.

A source revealed to HollywoodLife.com: ''Rob says he is having the best sex of his life. Apparently, she's very flexible and very uninhibited.

''He's in heaven. He's just fully in lust with her. He can't keep his hands off her. He even makes out with her in public, which is not usually his style. It was never that way with Kristen [Stewart; his ex-girlfriend], but this girl is loosening him up.''

Meanwhile, the 28-year-old actor's friends are believed to be ''bracing themselves'' for an engagement announcement.

Another source revealed: ''Robert has been looking at rings although an actual wedding is a long way off.

''He knows things are moving fast, but he wants to show his commitment. Everyone is bracing themselves.''

The 'Twilight' star is expected to visit the 'Two Weeks' hitmaker - real name: Tahliah Debrett Barnett - at her family home over the festive period.

The source added: ''Rob will be visiting Tahliah and her mum in Gloucestershire over Christmas.

''He's on a charm offensive as he really sees this relationship going the distance.''