I fail to see the insult here. Is the goal to insult the boyfriend, or their significant other? If it's to insult the SO, it's doesn't really mean much. You are judging them based on their association with someone else. A more apt insult would be "you could only attract people who drop common loot"

If the goal is to insult the boy friend why not just address them directly and say "you look like you drop common loot when you die"?