I guess this question is just for the married people. Have you ever dated someone and within hours, days, or weeks knew that this is THE ONE? How soon could you tell? Did you tell the other person as soon as you knew? When did you let your family and friends know that this person was THE ONE with whom you wanted to spend the rest of your life? Aniston 'thinks Mayer could be the one' Tuesday, May 20 2008, 11:03 BST By Beth Hilton, Entertainment Reporter Rex Features Jennifer Aniston has reportedly told friends that she is in love with boyfriend John Mayer. The couple were first spotted together in Miami last month and the 39-year-old's feelings have quickly become serious. A friend told Star magazine: "Jen thinks John could be 'The One' and that she has fallen for him - hard! She's usually pretty cautious when it comes to dating but, with John, she has decided to follow her gut feelings." Talking about the musician's previous relationships with stars such as Jessica Simpson, Cameron Diaz and Minka Kelly, the source added: "[Jennifer] has heard all about his past and his womanising ways, but doesn't see him like that." Mayer is rumoured to share Aniston's feelings, despite previous concerns that he may be interested only in a summer fling. A pal of the singer is quoted as saying: "He had become disillusioned with some of his earlier relationships, but he thinks Jennifer is gorgeous and he loves her sense of humour."