The card game didn't have the same audience as the comments made. Also you are making assumptions about how she plays the game and what she would find funny.
I do believe the person intended the joke to be private. It wasn't smartest or most mature thing to do, but I don't think it's much different from a couple guys texting each other jokes and Adria just happened to caught a glance of their cellphone screen.
If I may be so bold as to ask, in your opinion, are there any minimum requirements for being offended? That is to say, if apples offend me, and you're eating an apple, is it noble of me to speak up?