It's a car seat. Shouldn't I be upset?

While pregnant, I've handled everything. The registry, finding furniture, assembling the crib, pack and play, installing a ceiling fan while 6 months pregnant, EVERYTHING.

I asked my SO to install the car seat in the car. I can do it myself, but I NEEDED to be able to tell myself he contributed. After two weeks, he finally put it in the car. I never said a word about why it took so long.

I look at it... and it's on the rear passenger side. (Little note- HE was in a car wreck on the rear passenger side a few years ago that nearly killed his family- just FYI)

I came inside and very carefully said "thank you for installing the car seat, but why is it on the passenger side?"

Him: that's where the instructions said to put it.

Me: that's weird. I assumed it's safest in the center.

Him: I thought so too. I even looked it up and everything says it's safest on the side.

I dropped the conversation because why would he lie about something like that? It made no sense so I assumed he must be telling the truth and I was the one making assumptions.

Fast forward to yesterday... something just didn't feel right. So I looked it up. Sure enough I can't find anything anywhere that says what he claims. I even downloaded the instructions for the car seat.

When confronted he starts acting like I'm the crazy one and "I didn't lie... I just used a poor choice of words" "I didnt lie, I just didn't explain every little detail" "I didn't lie... you're just a bad mom because we have two cats"

Seriously... he was trying everything in his power to take the heat off of him. I'm not as mad that he installed it wrong. I'm MORE mad that he would rather lie about safety than to admit that he did something incorrectly. This is why I do everything myself.

It turned into me taking my ring off and him saying I don't deserve it. Then telling me that his whole family thinks that I lied and told him I couldn't get pregnant so that I could trap him (which is ridiculous since we had a full blown conversation about whether to start a family for two months, then the first time we decided to have Alex without a condom we got pregnant immediately. Also... if I wanted to "trap" a guy, wouldn't I want to STAY with him?!) the only way his family and friends would think my child is an accident is if HE was putting those thought in their head.

Am I being hormonal? I've been so angry about this whole thing for two days straight I can't even tell. Would you be mad? What am I supposed to feel?