The Spears family is never short on surprises, and today's announcement that Juno Lynn Spears' sperminator Casey Aldridge will go from babydaddy to fiance is one of the most pleasant ones we've heard in years. Casey, who's all of 18, apparently gifted Jamie-Lynn with the extraordinarily detailed-in-description "rock" a few days ago, and People reports that Spears has been flashing it around ever since to friends and family. All we're left wondering is what kind of party the heavily preggers Jamie Lynn will throw come April 2nd, the date of her 17th birthday. Our suggestion? An Abba-themed 70s dance-a-thon, during which JL will sing/cry her way through "Dancing Queen, young and sweet, only seventeeeeeen" over and over and over. [People]