The 31-year-old is keen to tie the knot and start a family, reported Showbizspy.
"She refuses to fall into that trap again with her new guy. Britney told David she wants a firm commitment that he wants to marry and give her a child - or get out of her life for good.
"To Britney's surprise, David presented her with a modest gold ring to prove he's totally committed to her. David is planning a more formal engagement with Britney later this year, but he wanted to give her something now to show her he's in this relationship for the long haul," a source said.