WTS 8 month pregnant wife. Cheap!

It's been a long time since I've been as upset as I was last night...

Gretchen had some friends over and we were watching 'The Office' together.
I had completely forgotten about the whole event until I walked through the door and found that we had company.

The night was going pretty good; good food, a few laughs. But I noticed that Gretchen had left the lviving room and was brooding in the kitchen while putting the dishes away. I called out to her from the livingroom:

"Hey hun, you alright?"

She kinda snapped at me and said: "I'm fine..."

Of course, her abrupt response even caught the attention of our guests. Needless to say, they saw something was up and decided to call it a night. It was late anyways...

So Gretchen comes into the living room and sits down on the couch and begins to look sorry for herself...

It reminded me of something my 4 year old son would do.

So after some questioning, I found out that she was mad at us (I say us, us being me and our two guests) for not offering her the couch while she was lying down on the floor.
Apparently, she was uncomfortable on the floor and she was mad that I wasn't chivalrous enough to offer her the couch spot.

I tried to tell her that I didn't notice and that it wasn't some concious decision to let my 8 month pregnant wife lay on the floor. If she had only asked me for the spot on the couch, I would have gladly given it to her.

But that wasn't enough for her. She was mad at me for not noticing. She felt that she shouldn't have to ask.

I got mad.

"I can't read your mind and you are accusing me of being selfish/inconsiderate based on the fact that I didn't offer you the couch!"

I'm not a chivalrous person by nature. I know that and she knew that long before we got married, but here she was being mad at me for something I am not.

Let me say it again, I was furious.

We fought back and forth because I refused to apologize for something I didn't do. Something deep inside me refused to back down and accept any responsibility for what had happened.

I'm very good at taking blame. Definitely to a fault.
I will take responsibility for actions that are not my own and it has crippled me as a person.

But not this time.

Gretchen was devastated that I couldn't offer the smallest of apologies, but I dug my heels in based on principle.

I don't know who is wrong here.

Me for being stubborn or her for being unfair?

I have no idea what happened to this marriage...