It looks as though Katy Perry and John Mayer are still very much on!

The on-again, off-again couple were most recently spotted together at Perry's birthday bash at The Magic Castle in Los Angeles, and leave it to Perry to get into the Halloween spirt and require her guests to wear costumes. Sounds like her public persona might be mixing slightly with her personal life.

The soon-to-be 28-year-old singer dressed up as a vampire, and may have drawn her inspiration from the 'Twilight: Eclipse' movie because she donned a cape, red contact lenses, and a crown. Rightfully so, her look wasn't complete without a pair of fangs. Mayer must be a fan of the series 'The Walking Dead,' because he chose to be a zombie hunter, and even went the extra step in wearing a prosthetic nose and chin.

The pair looked happy to be together, which is a welcome change from their get together for his birthday dinner last week. Accompanied by Mayer's father, the two appeared glum and bored during their time together, but nothing puts a smile on a person's face like a good ol' Halloween party.

Or maybe they're just into the role playing thing and Mayer has something else in mind.

Watch the Katy Perry 'Wide Awake' Video