Penelope Cruz, Spain's hottest screen goddess, Almodovar's muse and current girlfriend of the Oscar-winning actor Javier Bardem, has launched a second set of clothing designs for the fashion chain Mango with her sister, Monica.

The collection, unveiled in Madrid this week, is inspired by Brigitte Bardot and summers in St Tropez. It consolidates the Cruz sisters' debut last June for the Spanish high street retail chain, and confirms Penelope's status as a style trend-setter as well as a movie star.

Penelope Cruz, whose romance with Bardem has Spaniards aflutter, is preparing to shoot Los Abrazos Rotos (Broken Embraces) – her fourth film with her favourite director, Pedro Almodovar. In the autumn, she and Bardem will work together on Rob Marshall's film adaptation of the 2002 musical Nine.

The relationship between Spain's two leading pin-ups is eagerly celebrated in the nation's press, although the pair are extremely discreet. Cruz kept in the background while accompanying Bardem on his trip to Hollywood, where he won a best supporting actor Oscar for No Country For Old Men. But she reportedly became friends with Bardem's mother Pilar, the scion of a great theatrical family, to whom he dedicated his Oscar.

He and Cruz became an item last summer, long before he had to endure "the most horrible haircut in history" for his role in the Coen brothers' No Country For Old Men, which he reckoned would condemn him to months of celibacy. The couple met while filming Woody Allen's Spanish-based romantic comedy Vicky Cristina Barcelona, which is released in the autumn. Cruz and Bardem star alongside Scarlett Johanssen. Reports at the time romantically linked Bardem with the blonde New Yorker; the Cruz connection emerged only later.

That was the first time Bardem and Cruz had shared a screen since their explosive debut in Bigas Luna's Jamon Jamon in 1992. They apparently clicked off-screen too, but each was seeing someone else at the time. The steamy Jamon Jamon became a global hit and propelled the two young unknowns to national, and later world, stardom.

Madrid gossip columnists have suggested that "Pe", as Cruz, 33, is known, is keen to settle down with Bardem, 39, and have children. "My love life is wonderful," she beamed atthe Mango launch, adding that she wanted to "spend more time at home".

Monica Cruz, 31, is thought to be the creative spirit behind the Mango line, although the sisters say they have been making frocks together all their lives. Monica has followed her sister into movies and is currently filming the romance Caminando (Walking), in which she plays the daughter of a flamenco school director who falls in love with a US Navy pilot. By coincidence, Pilar Bardem also appears in the film.