Step-kids

Does anyone else struggle to bond with their step kids or is it just me?? I try so hard to have a good relationship with him and I just feel like he doesn’t like me some times. I have been in his life since he was 2 and he just turned 5. I have my own daughter from a previous relationship that is 4 now and they get along good for the most part. I’ve noticed lately that he has gotten very aggressive and it makes me feel like I’m walking on eggshells in my own home when he is here. He tries to “play fight” with my daughter and it gets out of hand quickly. I have caught him whispering to my daughter telling her to do bad things (to hit me, to hurt the cat, to throw stuff). I feel like it isn’t my place to get onto him so I try to just let my husband handle it, but he isn’t always around when things happen. When things happen I try to nicely explain to him what he is doing wrong and I try to make it clear that we have rules in my house. He always screams, “I want MY mom!” or he will just get mad and go to his room and slam the door as hard as he can. I just don’t know what to do and it’s getting to the point where I dread for him to come visit on the weekends. I hate to say it, but his attitude literally just ruins my day. I hope it’s just the age he is at, but I’m slowly losing hope of ever having a good relationship with him. He feels entitled (because his mom never tells him no and spoils him with crazy expensive gifts all the time) and if he doesn’t get his way all the time then he loses his mind. Just now, my daughter didn’t give him a sticker right away so he took her tablet away from her and was about to throw it in the trash before I caught him.... I literally just want to cry! I don’t know how to make things better/easier when he’s here.