Isabella wants to continue having fun with you

You ask Isabella point blank if you can be expecting to fuck her on the regular now.

She is caught off guard by the directness of your question. She had sort of assumed that this was a one-time experience, but now that she's faced with answering the question she realizes that she can't say that. Isabella knows herself well enough to know that as soon as she gets home she's going to be obsessing over your cock. She still might not really even like you - but she's damned into that tool you've got between your legs. If she denies herself access to your cock she'll just be making the obsession worse.

"Yes," she says in response to your question.

You just smile in response, causing Isabella to keep talking out of nerves.

"You can fuck me whenever you want, John. It would be cruel to deny you these babies," she says indicating her breasts. She looks over at Emma who is sitting naked on the bed with the two of you. Both girls know that it's hard to be satisfied with just Emma's small titties to play with.

Just like that, Isabella agreed to be your slut without needing to give her any Slave4U.