Congratulations are in order because Diplo is a dad… again! The DJ — who has been romantically linked to Katy Perry for some months now — welcomed baby No. 2, a boy reportedly named Lazer with his ex-girlfriend, Kathryn Lockhart (with whom he also fathered a 4-year-old son Lockett).

Soo where does that leave Katy? Should we congratulate her on being a step-mom? A crazy aunt you’re not sure how you’re related to? Daddy’s “special” friend?

Whatever role she plays — she’s not alone! Check out four other twisted celebrity relationships — where the guys moved one while their exes had little ones on the way!