<human>: Gf of 4 years asked me if it would bug me if she went to a strip club with her male coworkers. I guess it something they do once in while at her office. She's the only girl there.  I told her that it would bug me.  She asked me why and I told her I wasn't comfortable with her going to a sexually charged environment with a bunch of guys.

  She said strips clubs aren't sexual for women as opposed to men and that she wouldn't be mad if in the future I ever went to one with my friends . I've never been to one but I admitted it wasn't out of the realm of possibility since bachelor parties sometimes involve strip clubs. In the end I told her that I don't want to be with a girl that was completely OK with going to a strip club with male friends/coworkers. I told her that if it was with female friends I'd be less uncomfortable with it but that not what she was originally asked about.

  She said I was being unreasonable and that I was promoting a double standard. She also didn't like what she considered an ultimatum from me. She then asked me if I thought she belonged to me.  I admitted that I saw her as belonging to me (as in MY gf) but I also told her that she was free to do whatever she liked but  to not expect me to pretend everything was OK afterwards. The topic was dropped soon after but now I feel something is wrong here. 

 I feel like I don't see my gf the same way now.  I never really imagined she would ever want to even be in a strip club with a  bunch of guys because she's always complaining about how guys can be "such creeps".  Why would she even want to go?  She says it would be "funny"...  I don't get it.

Can you condense the text into a few key points?
<bot>: Gf asked me if I would be ok with her going to a strip club with her male coworkers.  She got mad when I said yes.  Now I'm confused as to why she would even want to go.