The `California Gurls` singer - who got engaged to the British comedian in December after a whirlwind romance - still likes to go out and party with her friends occasionally, but her fiance`s sobriety has had a "good influence" on her.

She said: "I still love to go out with my friends and I still like Pinot Grigio. But I`ve learnt from some of my hangovers and I don`t drink as much as I used to. My last big night out was probably the Coachella festival.

"I`m happy that Russell is sober because it`s had a good influence on me. It steers me in a more positive direction."

Although reformed womaniser Russell - who has overcome drug addiction and alcoholism - has had a positive effect on Katy, she isn`t responsible for taming him.

She added to the UK edition of Glamour magazine: "It`s not about taming. He changed for himself. Everyone knows no one will change unless they want to change themselves. It was a cosmic collision.

"We work together well in the relationship because there`s no arguing. It`s important to have your communication on the same level."
sections: Celebrities