My GF became defenseive when I asked who sent her roses on her Birthday....

[mustlovedogs]

OP, you're creating this drama by putting yourself in the situation.

 

You know this is how she acts. Therefore, you shouldn't be surprised. So your staying is just creating your own problems.

[boltnrun]

If you didn't enjoy drama you would have bailed out of this permanently 4 years ago, when she cheated on you. Instead of, you know, going back for more.