Bisexual struggles

So I’m bisexual and I’ve always been very open about it, I love that part of me. I’m in a relationship with a man and we’ve been dating for almost 2 years. He doesn’t care that I’m attracted to girls, in fact he’s like really okay with it. I’ve mentioned I wanted to do stuff with girls/flirt, and he said he doesn’t mind. He wants me to if I want to. I watch only lesbian porn bc to be honest it gets me VERY horny. I enjoy flirting with girls but I still feel kinda guilty. I’m a very loyal girlfriend and would never do anything behind his back but it still feels wrong in my head. Like I would never let him do the stuff he lets me do. I want to have sex with a girl because I haven’t had real lesbian sex (besides with my best friend when we were very drunk a long time ago). I want to marry this man but at the same time I want to be able to have had real lesbian sex, and finally be able to have that experience. Advice anyone??