Discipline for a 4 year old. What is working for you?

My heart hurts every time I have to get stern with my little guy.Usually it’s me (father) stepping in when mom has asked our son to stop doing something more than a few times. Tonight he flushed his toothbrush down the toilet for the 3rd time and thought it was hilarious. Have to admit, I can see why it is indeed comical, however he knows it’s wrong. I sent him to bed with no cartoons or stories (our nightly ritual) and it crushed his little heart. He wailed in his crib for about 20 mins before I couldn’t take it any more and pulled him out. I did let him watch a single cartoon in the living room but held firm on not letting him watch on his tablet right before bed.I grew up in a strict, spanking family and I have to say it seemed to work well looking back. Before I did something that might end up with a swat to my butt, I thought about it and 9/10 times decided against it. I hate the way he looks at me when I get in the middle of an argument between he and mom, but I know it’s needed. Mom is really soft hearted and is against spanking. I just want to be consistent with him and a small part of me wants him to give that same ‘look’ to mom when he gets in trouble. I don’t want to always be the bad guy, which these days it seems I’m the only one. The kid is amazingly smart so it seems there is a discussion in his head whether the punishment fits the act right before he does something. However I don’t know how to take advantage of it.There is no consistency between mom and I, thus it sparked a large argument between us tonight. I have been asking for consistency since day one and Mom likes to give in every time. Not sure where to go from here because I would default to a single spanking per event whereas mom would say it’s fine he’s a baby. Let’s be clear here, a spanking to me is a single solid swat right on his butt, that’s it.What is or isn’t working for you, the parent of a 3.5-4yr old? Thoughts? via /r/Parenting http://bit.ly/2XfaPAy