Mr Skin favorite (check out her nude scenes in Closing the Ring!) Mischa Barton celebrated her 23rd birthday yesterday. And she celebrated in high style!

First she hit the Dior fashion show in Paris, where she showed those fashionistas how to really wear a strapless dress. Slipping down. Showing some areola. A hair away from a Mischa Barton nip slip.

Afterwards, she headed out to party with friends and capped off the night by laying a big lesbian kiss on female friend, supermodel Irina Lazareanu!

As you can see, Ms. Lazareanu then made use of her see-through dress to pop some mega-nipple of her own. Now that's a birthday gift we'd love to unwrap.