Spanking children

So I believe in giving my child a little spanking on the butt when he continues to not listen when I tell him no. With that being said this weekend we were at his moms and his stepdads hous and my son was playing in the dog water after he was told no and so his stepdad went over and gave him a spanking, I don't know if it's the hormones or not (I'm 20 weeks pregnant) but it pissed me off I don't feel like he had the right to spank my kid! My son is 14 months old. I'm just curious if you ladies agree or if I'm just hormonal 😂☺️