Badly, but she doesn't need much convincing

"I suppose you can't, but then again, how do I know you won't slit my throat in my sleep?" You sigh heavily.

"The truth is someone WILL use her. It will be either me or members of gangs you mentioned before. What is more important she will bring you in trouble. I could have kill you. I could order you to strip and **** you, too. But it doesn't have to be that way." Suddenly you slam a finger in Gwen's recently deflowered asshole forcing her to cry out in pain.

"Please... Stop him Lea!"

"You see?" You say triumphantly " Your friend is a parasite who expects that you will get her out of trouble with her doing nothing!" You pull your finger out of Gwen and move it to the girl's face "Lick it clean or I'll hurt you again!" You order and Gwen does exactly like you told wrapping her trembling lips around your finger. Your dick twitch as you imagine her doing the same with your dick but this have to wait. All your attention is on Lea.

You push Gwen away in direction of Lea. "Here. You can have her. I'll leave if that is what you want. Or you can have an ally who asks for a reasonable reward of owning an otherwise useless asset"

Lea's slightly watery eyes move from you to Gwen who lies on the asphalt sobbing wildly. You are sure that she is considering your offer but it goes against her morals

"Gwen!" Lea faces some inner struggle but she made her decision "He is fucking right! I gave you our only gun and told you to be careful but you got yourself ****. It is your own fault. I won' reject a valuable ally to protect your cunt."

Gwen then sobs even more, but Lea's eyes are a bit glassed over, and she is unsympathetic to her former friend's plight.

Bits plagiarized from a different thread, written by Hvast (because the dialog was already better than anything I could come up with)