Kissing on the lips

I grew up with a family who kissed us on the lips. My partners family never grew up kissing kids on the lips. My partner doesn’t want anyone in my family kissing our child on the lips at any age, I told my mom this boundary and she nearly melted down saying it’s a “power trip” and that she should be able to kiss her grandkid on the lips if he or she runs to her asking for a kiss. I said it’s not necessary to kiss on the lips if you could kiss on the lips or cheek instead. We could not come to an agreement and now she’s pissed that I would agree with his boundary. What do you guys think?