Britney Spears allegedly left a restaurant without paying.

The 'Till The World Ends' hitmaker and her boyfriend, David Lucado, reportedly walked out of The Cheesecake Factory in Thousand Oaks, California after eating lunch, but forgot to settle their bill.

But a source insisted the 32-year-old star simply made a mistake and told gossip website TMZ.com that she feels ''horrible'' about it.

The couple, who started dating in March 2013, had an appetizer and a salad before telling the waitress that her bodyguard would pay the $30 bill and leaving with a doggie bag of leftovers.

But the security guard never gave the waitress any money, as he thought Britney, who has sons, Sean, eight, and Jayden, seven, with ex-husband Kevin Federline, had paid.

A source recently revealed that Britney and David are thinking about having a baby together when her Las Vegas residency ends next year.

The insider said: ''Britney cannot wait until the Vegas show is done because she wants to start a family with David. She says she will get pregnant as soon as the show is finished!

''David is always with her in Vegas and they act like an old married couple together. He is really good with her kids and has taken to the father role pretty easily.''