London, Jan 6 (IANS) Director Paul Thomas Anderson and actor Daniel Day Lewis became so intimate when they worked on their latest movie 'There Will Be Blood' that they now refer to each other as 'boyfriend and girlfriend'.

They forged such close bonds while working together that their wives were angry, reports contactmusic.com. Anderson says: 'At best, it feels that you are connected to each other. You are playing the same tune.'

Anderson said, 'There is this kind of line between myself, the camera and Daniel that is pulled tight. When it was going well, it just felt like that. We're still trying to figure out who is the girlfriend and the boyfriend in this relationship.'

Anderson recalled that when he first met Day Lewis and called him a few days later, he left a message saying: 'It's your girlfriend.'

'It feels like that. You are in a relationship with someone so intimate, every single day. I dare say there were moments when our spouses were jealous,' the director said.