Britney Spears won't rule out a third marriage.

The 'Till The World Ends' singer - who split from husband Kevin Federline in 2006 after two years of marriage, while her union with childhood friend Jason Alexander was annulled in January 2004 - has been dating agent Jason Trawick for two years and says she's very happy with him and would consider tying the knot if he proposed.

When asked if she has plans to marry, Britney told Us Weekly magazine: "Maybe. Never say never!

"We have such a great time together! He makes me laugh, and we are so comfortable being ourselves.

"I've never been happier."

Britney - who has two sons, Sean Preston, five, and four-year-old Jayden James, with Kevin - has previously spoken about Jason, saying she loved how grounded her kept her.

She said: "We're really normal. We just like to watch movies. We work out a lot. We love to work out. We do stuff together like that. We take walks."

The 29-year-old star recently revealed how her family life comes first and schedules her work around it.

She explained: "I'm usually pretty busy when I'm not working. I have two children, so I usually get them up in the morning, and I'm usually at the gym, and I help cook dinner sometimes ... a lot of the stuff that I do I do early in the morning when my boys are at school."