Most Helpful Girl
They call you when they need you, ask you do them all kinds of favors, never present you to their friends or family, never make your relationship official, usually not spending the night, invent excuses when you planed something for them and ignore you when they are busy, making you wonder what's happening here, but always succeed to make you believe they love you and want you in the future.
Most Helpful Guy
They usually act really cute and start stroking your cock. Just tell them, "Baby, I'll do anything for you if you put those gorgeous lips on me.."Then fall asleep, mumble that you're not a sex slave, and not put here on this her for her enjoyment.