Max George's success has put his relationship under huge pressure.

The Wanted singer recently confirmed he and British actress Michelle Keegan - who got engaged in June 2011 after a whirlwind romance - are no longer engaged, and pals think the hunk's US success put a lot of strain on their union.

A source said: ''When they got together Michelle was the bigger star but now he's really taken off. He is going to be spending more time In America so they will be spending more time apart. She wants somebody who is going to be at home.

''They called off the engagement because it was putting a lot of pressure on them both. There is no time to sort a wedding at the moment.

However, friends insist their relationship is solid and the couple are planning a holiday to spend quality time together when things get less hectic.

The source added to new! magazine: ''The truth is they are two kids from the same area of Manchester who have a lovely relationship. They see each other when they can. They talk on Skype and are hoping to go on holiday this year when she's quieter and he is back from America.''