Question: Axolotl popping mouth at me?

[Loopy Leo]

So my lotl keeps popping his mouth at me sometimes its if I do it first which is what the sound is in the attached vid but sometimes he just does it anytime I look at him. I thought it could be because he's hungry or something but it happens even after feeding him. I just want to make sure I'm not doing anything wrong to cause this behavior.

 

[SamAxolotl]

Please note I'm no expert! But as no one else has words of wisdom for you, here are my thoughts.
Your axolotl seems happy, healthy and loved. Axolotls are adorable and it amazes me how they interact with people. I read once that a great rule for owning axolotls is that if the axolotl doesn't seem concerned, then there is generally no reason to worry.
Your axolotl is showing no signs of stress, illness or mistreatment. In my opinion, I believe your axolotl perfectly fine.