Intimate celebration: Clutching his Best Supporting Actor Oscar, a jubilant Javier Bardem celebrated with his girlfriend Penelope Cruz and mother Pilar Bardem on Sunday night

Cruz, 33; Bardem, 38; and Pilar, 68; first went to the Miramax party, where Cruz chatted to the Coen brothers and Sir Elton John, before heading to Prince's bash and then to the club Villa.

The couple, who usually try to keep their relationship private, were glued to each other's sides.

Despite arriving at the Academy Awards separately, away from the photographers later on, their coupledom was obvious to fellow partygoers.

An onlooker at Prince's party said: "Javier had his arm around Penelope and his Oscar in his hand."

Shock: Javier Bardem celebrates with his mother Pilar Bardem as he is announced as the Best Supporting Actor Oscar winner

The couple looked effortlessly chic as they fluttered between three post-Oscars bashes through the early hours of Monday morning.

And even after all that including free-flowing champagne all night they were still bright-eyed as they got in the car to go home at 4am.

The pair started dating last summer on the set of Woody Allen's Barcelona-set movie Vicky Cristina Barcelona.

Their acquaintance goes back a long way, they co-starred in the critically-acclaimed 1992 drama Jamom, Jamon, which made Cruz a household name in her native Spain.