From Halopedia, the Halo wiki
Love Machine is a Bungie.net multiplayer medal available in Halo: Reach. It is earned by getting 7 kills in a game against players that have Heart Attack. It is represented by the Heart Attack icon on top of a red six-pointed star. The medal does not appear in-game and can only be viewed on Bungie.net.
On March 31, 2012 Bungie.net ceased updating Halo game stats and player records, transferring all record-keeping responsibilities to Halo Waypoint. As Love Machine could only be viewed on the site, it is effectively no longer awarded.