"She had a tea party under water" or "she had a tea party underwater"?
It is the adverb "underwater" that gives the meaning you likely intend (see the photo in my last post). The prepositional phrase "under water," while possible, would indicate that she was not in the water. To have a tea party underneath a huge glass aquarium, for example, would be to have a tea party under water.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .