WWYD - Babysitter pinching kids

Good morning...I have a dilemma...my 2 year old started pinching is brothers this week and saying “You’re Welcome”...which was part amusing part annoying.

A day after the pinching started, my two year old told me one of his teachers at daycare is pinching his legs. He told me like this, “A pinch L’s legs. L cries.” (A is the teacher, L is the 2 year old).

I obviously don’t like this one bit and because my son’s description is not vague, I suspect there is truth to it. He has mentioned the pinching part 3-4 times but he doesn’t always say the crying part.

WWYD - would you talk to the teacher first or go directly to the daycare owner?

Thanks in advanced for all the responses.