The `Hold it Against Me` hitmaker`s boyfriend Jason Trawick - who has been dating the pop star for around two years - plans to whisk her away on holiday when her `Femme Fatale Tour` ends in Puerto Rico on December 10, and he is "very likely" to pop the question.
A Spears family insider said: "Britney and Jason discuss marriage all the time. Britney is truly in love with Jason, and well, Jason has loved her for a very, very long time.
"Jason adores her two sons, Sean Preston and Jayden James. Jason is planning on taking Britney on a secluded getaway once the tour wraps, and it`s very likely he will pop the question at that time."
The 29-year-old singer - who has been married twice before, to Kevin Federline, the father of her kids, and Jason Alexander - would need a judge to formally sign off her marriage as she is still under her father Jamie`s conservatorship following her much-publicised breakdown more than three years ago.
But she would be allowed to get engaged without requiring any official approval.
The source added to RadarOnline.com: "When Britney does get engaged, her father`s attorneys will notify the judge in her conservatorship case. It`s extremely within the realm of possibility that the conservatorship will end, and then Britney will get married. It will be a very smooth transition."
The blonde beauty`s mother Lynne and Jason are said to be "very close" and her family are "looking forward to the day that Jason will formally be a member of their family".
Earlier this year, Jason visited an exclusive Los Angeles jeweller to help him design the perfect ring ready for when he proposes to the `Toxic` singer.