Louis Tomlinson will never cheat on his girlfriend.

The 20-year-old One Direction star - who has been in a relationship with Eleanor Calder for more than a year - is mobbed by girls on a daily basis but says he isn't tempted to cheat because he wants to set a good example for his own sisters.

Louis told The Sun newspaper: ''It's important for me to treat a girlfriend with respect.

''My mum would be horrified if I behaved any differently - and I have sisters, and would hate for them to be treated badly by guys.''

The 'What Makes You Beautiful' singer also revealed he was initially worried about being branded a love-rat simply because he is in a boyband.

He said: ''I was worried about my reputation at first. I remember I sent Eleanor's mum a few text messages saying, 'Please don't judge me thinking I'm like the stereotypical boyband type who is going to go around and sleep with everything that moves.'

''I was trying to convince her I'm quite a good lad but I didn't really need to.

''Her family are really cool actually and very understanding of the situation.''