Do u get kissed on the lips by ur own mom?

So I find it really weird that my own mom gives me a peck on my lips. This happens in my entire mom side family. My mom, her sister and her brother's wife all have this in common- pecking the 3 of us(me and my 2sisters) on the lips. My married sister came back home after 1year and in the airport itself my mausi and my mom started kissing her on the lips infront of her husband. After coming back home I objected to this and my mom laughingly said that she will kiss my future wife on the lips infront of me. Like wtf? I consider lip-kissing is only for couples. Am I wrong?