Brad Pitt and Angelina Jolie will mark their marriage with matching tattoos.

The 'Moneyball' actor and his actress fiancee - who raise six children together - already each have multiple pieces of body art but want to commemorate their union with some ''weird'' new inkings.

A source said: ''[They are deciding] with what and where they will ink themselves to mark their long-awaited marriage.

''Brad really wants to do something special, and frankly, a little weird to mark the occasion, and they want to get the exact same design, in the exact same spot in their bodies.''

The couple are planning to have the designs etched somewhere that isn't always visible and Brad, 50, is particularly enjoying coming up with the right piece.

The source added to RadarOnline.com: ''Brad is like a teenager again as he and Angelina decide on their matching tattoos. He's let Angelina help him pick out tatts in the past but this time it's a real collaboration.

''Don't expect it to be something that's visible when they're out day to day. They might just acknowledge to the press that they did it, but keep the actual content of the tattoos as their love secret.''

Brad and 38-year-old Angelina - who got engaged in 2012 - are expected to marry later this year.