<human>: Can you condense the text into a few key points?

I'm kind of disappointed to be asking about advice so early in a relationship.  We've known each other for a couple years but since becoming an item, I'm learning things about the way she interacts with me that I did not expect.

There have been a number of moments that my gf has been referencing her ex in benign but, in my opinion, unnecessary ways.  The most recent example is she was getting out of the shower and I had come into the bathroom after getting dressed.  She liked my new shirt, and said "I'm so glad you like color, my ex used to only dress in black. Always just black." 

Out to dinner: "I'm so glad you like Thai food, my ex never wanted to try different things."

"You're so creative - my ex would never think like that."

While most of the comments are actually indirect compliments, after the comment about my shirt I said politely, "You're referring to this ex of yours from three years ago, right?" "Right, he was the only one I considered serious besides you." "Well, can we just be here together?  Your relationship with him happened at a different time and he doesn't belong here.  I don't want to be compared, it's just me and you here."  "Fine, Jesus! Why are you so sensitive?"

Normally, my SO is a mature individual and I never expected this kind of thing.  It's like becoming an item has unlocked her "freedom" to drop keeping up certain social manners and just say whatever she wants.

I asked, "You wouldn't be bothered if I kept saying little things? Oh - you don't like coffee? My ex loved coffee.  Oh - you don't like action movies? My ex never cared for them either." Her response: "I wouldn't care!"  ... she says that now. If I kept doing things like that, I think it actually would bother her and she doesn't realize it yet.

Thanks for reading.
<bot>: SO keeps mentioning her ex in little ways and reacts badly to my request that she not do so.  Red flag?  Am I crazy?