<human>: Give me the gist of the text in a nutshell

I took my girlfriend(dating a little over one year) out to an nice restaurant for New Years eve where we ate great food and had a fantastic time.  We didn't have any plans for afterwards and I had been invited to a coworker/friend's house for a New Years party.
Some back story is required pretty much everyone at my small IT takes an irreverent approach to humor (Cards against Humanity is a common game at company events).  My girlfriend is what I would describe as a feminist but I've never actually seen her get offended about a joke.

Anyway, just as a pro-cation, I warn her that things could get beyond her taste at said party and we establish safe word for if she wants to leave.  We go to the party where everyone else had been drinking a bit and were playing a fairly non-politically correct card game (Lots of jokes about sex, dirty things, one guy I didn't know said something about rape ounce or twice that I did not find funny).

She pretends to have a good time, looks at her phone a lot plays along with the game... all is well with the world... or so I think.   We leave around 2am and she informs me that she felt extremely uncomfortable the entire time and was extremely offended and doesn't talk to me the entire ride home.  Once we get home, she tells me she can't believe I was laughing at some of the jokes that were told during the game and she can't believe I couldn't tell she was uncomfortable and wanted to leave.  She also brought up that she broke up with a past boyfriend for doing something similar... she brought this up six times.

She never once informed me that she wanted to leave nor brought up the safe word we established.  She came over and apologized profusely the next day but I still can't help feeling crushed.  I'm not sure where to go from here.  I feel like the bringing up of her past break up was very threatening and I can't get some of the incredibly hurtful things she said out of my head.  Here's to starting 2015 with a mild case of depression.
<bot>: Played non-pc card game at New Years Party.  Got called a terrible human being by SO for laughing at shock humor jokes.