If a Pokemon learns an HM move, will it be able to forget it?

Question

Salamence learns Fly, but since it's an HM move will they give you that stupid message?

Answer 1

Yes. The "stupid message" will appear, since HM moves can not be deleted by other moves/TM moves. The only way to have an HM move deleted is by the Move Deleter, who can delete any move in the game from the Pokemon moveset. The Move Deleter can be found in Dendemille Town, along with the Move Relearner.

Links :Bulbapedia Dendemille Town Page