Mon cher and cara bella are not recognized as acceptable end clues because according to the Official TFWG Rule Book (Unabridged Version 17, Copyright 2016), in Section 07.0004, subsection B2.1, article VII, paragraph 7, lines 53 and 54, you will see that all contributions are required to be in English.
It's not my rule, I'm just passing along the information. The rule could be amended if there is a quorum among the senior leadership. If you'd like to file a grievance, please contact your shop steward.