You can't tell Facebook not to do that because your phone number and texts are no longer just yours at that point. Your friend has a copy and can do whatever t

You can't tell Facebook not to do that because your phone number and texts are no longer just yours at that point. Your friend has a copy and can do whatever they want with them, including share them with Facebook, the NSA/FBI/police, their friends, or anyone else they want to. If you don't want them shared with Facebook, don't give the people who are sharing them with Facebook a copy.