"I'm not saying you can't," Aaron said, smiling. "I'm just saying you should be careful not to let people be tempted to use you in that way if you don't want to be used in that way."
Other options:
no subject
"I'm not saying you can't," Aaron said, smiling. "I'm just saying you should be careful not to let people be tempted to use you in that way if you don't want to be used in that way."