I have to say it one more time, that I really appreciate all your answers
Im not sure that I have made it clear enough, but im not asking by permission from my girlfriend.

We have always had a very open relationship, and have did what we wanted to without any problems regarding the both of us.
I have already tried to smoke DMT once, but the attempt failed and nothing happened. Back then I didn't tell her it, and still haven't. But now when I want to try it for REAL the first time I want to tell her it. I think it's all about how I tell it to her. But im not sure what's the best way is. You can have done alot of research and have material ready, but as you guys said, I think she will do her own "research" once I tell her.
I can only say to her the best way how I want to experience some higher conciouss experience, and then I have to take it from there. Regarding to the experience itself, I want to know what my own conciouss is all about. I don't exspect any answers from the experience, but things have happened and changed in my life, that I want to get some perception on from another angle if you can say it that way. I started to question many things in this life after my father died when he was only 50 years old. I was 19 back then, and the doctors couldn't tell us what he died of, but that only 50-100 people died of unknown reasons like this every year. His heart just stopped one night, but the doctors couldn't tell us why. He got every test they had a few days before his dead and sent him home with the results, that he didn't had anything to worry about. Two days later when he woked up in the middle of the night, he just dropped to the ground. My mother tried CPR, but unfortunately it didn't help.
As said earlier I have had alot of thoughts after his dead. What is this life all about? how come a man that didn't have any diseases and lived a healthy life die at the age of 50.
After that horrible experience, I have learned that we never know what will happen, and you can only do what makes you happy and try to live your life the fullest. One thing is for sure. I have certainly become more spiritual after this episode of my life, but I have certainly also tried to figure out what's this all about.