Will was prepared to make a change, but hesitated. He was limited to one word to change, and looking at the sentence he had there was no way he could get what he wanted without something going wrong. If he changed anything about himself he and Carmen would still be siblings. He couldn't change Dylan without Carmen still flirting with him. He had the same problem if he changed Carmen herself. He could make her his girlfriend, but she'd likely be unfaithful, and still flirting with Dylan.
He didn't have much time, so he quickly tried for a new sentence.
"Dylan is a 22 year old man who wants sex with his friend Carmen."
Will had hoped for something that would allow him to change Carmen, but he didn't have much time. He'd have to settle for getting rid of Dylan for now.