Bradley Cooper is insisting on going grocery shopping with Lady Gaga to ''get in the zone'' for their upcoming movie.
The 41-year-old actor will make his directorial debut with the upcoming 'A Star Is Born' remake and is already bonding with his co-star by doing everyday tasks together.
A source said: ''It's a huge project for Bradley and he wants to build momentum.
''He's hanging out with Gaga a lot to get in the zone.
''He's been at her house and they've been doing bonding exercises, such as having brunch and going shopping. They share a love of vintage cars too and they're getting on like a house on fire.''
However, their pair's new friendship hasn't gone down well with Bradley's girlfriend Irina Shayk, who is said to be feeling frustrated at the amount of time the hunky actor is spending with the 'Poker Face' singer, who recently split from fiancé Taylor Kinney.
The source added to Britain's Grazia magazine: ''Bradley and Gaga have become so inseparable that his girlfriend is feeling quite left out.
''It's causing tension in the relationship - especially because they're not even scheduled to start shooting until next year - but Bradley is refusing to compromise.
''Irina already feels Gaga has become the third person in their relationship so she's dreading once filming starts and Bradley and Gaga are spending every day together.''