Porn watching.. Is this normal

My partner has been very distant and will often stay in bed after I have gotten up. Whilst I've been getting everything ready for baby before work, I've found out that my partner is watching porn. He's also watching it whilst I'm at work in front of our baby and even puts our baby down and leaves him to go off and watch it. He's been watching it during the festive period whilst I've been home with him.

I feel really low about myself and cheated. I feel like he's been waiting for any opportunity for me to leave the room/go out to work just to watch something totally fake and unrealistic.

I try my best as a mother and partner and I just feel totally disrespected. Would you leave? Or am I being unreasonable. I know that there are mixed views when it comes to porn but I feel this is overstepping the line. I've tried speaking to him but he can't give me any answers or even converse with me about why this has been going on. From what I can gather, he just thinks I'm some sort of house maid to do all the jobs and go out to earn money whilst he pleasures himself and ignores our son. I feel totally useless and worthless.