Britney Spears is ''totally smitten'' with Sam Asghari.

The 34-year-old singer - who has sons Sean Preston, 11, and Jayden, 10, with ex-husband Kevin Federline - has been single since splitting from TV producer Charlie Ebersol in June 2015, but has been ''quietly dating'' a number of guys in recent months and now thinks she's found happiness with the hunky personal trainer, who she met when he starred in her 'Slumber Party' video.

A source said: ''This is the longest Britney has ever been out of a serious relationship and she's made no secret of the fact that she's been desperately lonely.

''She's been quietly dating for the past year, but Sam is the first man she's met who has swept her off her feet and she's totally smitten.''

Sam shared a picture of himself and the 'Toxic' hitmaker last week on Instagram, but later deleted the picture, and insiders claim Britney is keen to keep their romance low-key at the moment until her kids get to know her new man properly.

The source said: ''Britney doesn't want to go public with Sam until the boys have met him properly.''

The blonde beauty has struggled with her weight in the past, but thinks Sam is good for helping her stick to her diet and exercise regime.

The source told Closer magazine: ''Sam has been ensuring she sticks to her fitness regime and they have been working out together, so Britney credits him for keeping her in such great shape.

''She's really happy and is hoping the tide has finally turned for her and that Sam can give her the fairytale ending she's been longing for.''