The opposite of friends with benefits
, friends with costs incur a negative benefit (a cost) on whoever they are friends with. This could include bothering you from time to time for favours or money.
Suman: Cynthia, can you please pick up a bottle of vodka for me and bring it to my house? I promise I will pay you back some day.
Cynthia (aside): I wasn't even headed to Suman's house... Now that's what I call being friends with costs...