Is he wrong or am I wrong?

So Ive been dating my bf for a year who’s NOT the biological dad of my 5 year old son, I’m always at his house we even plan on moving in with each other but when it comes to my kid doing something wrong or not doing something he always has a problem and a say, comes at me with a attitude and yells at me like a little kid. So today my kid was eating food that I bought him we told him to finish everything obviously he didn’t he said he was full went and threw the rest away we both were ok with that next thing I know my son tells me he’s hungry if he can get a banana and I was fine with that. My bf comes out the bathroom and proceeds to tell me how I’m wrong and yells at me like “cmon you don’t see what the fuck he’s doing” he’s just playing you saying he’s not hungry but goes and grabs food “you don’t ever do shit or discipline him” and I was on the phone like ok what’s the big deal? He asked and I told him go ahead, this isn’t the first time he says something about my son ITS AN EVERY DAY THING! Any thing he does he attacks me for it says I have poor mothering skills and honestly that’s fucked up and rude and very disrespectful of him to come at me for shit like that. I told him I don’t like how u come at me like a father figure rather then just telling me one time to fix the situation. He says my kid doesn’t listen to me and that I let him do whatever. Now he’s saying how he don’t wanna be with me no more meanwhile I’m pregnant with his kid.. what a mess over a dam banana also what should I do I try to talk to him but he’s stuck on that’s how he was raised and he’s going to respect him in his house