WoWDB

Any of the necklaces from  Love is in the Air will work for this achievement.  They all drop from Apothecary Hummel and any of them can be used by any player since it is a necklace.  Now you have a reason to roll for the item instead of passing on it every time!  (Of course, there was that one time in Cataclysm where the necklaces could be disenchanted.  Very, very nice way to farm for shards.  Blizzard fixed that relatively quick, though, haha.)

Listed for your convenience:

•  Choker of the Pure Heart
•  Heartbreak Charm
•  Shard of Pirouetting Happiness
•  Sweet Perfume Brooch
•  Winking Eye of Love

The use effect causes you to launch a rocket that explodes into two pink hearts.