Britney Spears and her boyfriend dress up as superheroes.

The 29-year-old singer - who is dating her former agent Jason Trawick - threw a party for her youngest son Jayden's fifth birthday this week, and while the young guests dressed up as their favourite comic book stars, she resisted the outfits, though she admits she is happy to wear a costume in private.

Britney - who as well as Jayden also has six-year-old Sean Preston with ex-husband Kevin Federline - said: "We've just had a huge birthday party for him yesterday! It was Spiderman and Batman [themed], he's obsessed, so obsessed!! We have four Spiderman costumes, so all the kids at the party had on costumes!

"Oh, I didn't dress up at all! Nooo actually me and ... I was going to say my husband ... my boyfriend we do that every once in a while! We're such Goubs! I'm so embarrassed!"

Although she enjoys dressing up with Jason, Britney insists she is actually a very boring person.

In an interview on the KISS FM breakfast show, she said: "I'm really kind of boring. I love my home and love my routine! I like my computer ... we're American so we like that!"

The 'Hold It Against' hitmaker turns 30 in December and she admits she is starting to feel old.

She added: "Oh my god it's crazy! I'm getting old!"