Discuss to her about the topic and try to grasp upon her opinion. If she feels disgusted about having a open marriage with you then you have to deal without sex until she is ready to be in the "sexual" mood. That's all I can tell you bro.

you ******* don't ever cheat on a person you idiot it destroys their trust forever

The very fact that you are even considering going with someone else suggests that you are not yet ready for the commitment of marriage.

Some very serious thinking and sharing seems required.

In any case move on and just be honest about your sexual appetite and needs wanting another partner to fulfill your dreams. At least she will not be ghosted. If she has invested feelings you have told truthfully and are not a smuck when years later you call her up and say Hi how are you friend?

Never cheat on your Fiance, this is one reason why I despise my father's choice. However I love him as a Dad. He never failed me as a Father, but did as a husband for my step-mother. Although I don't care much for my step-mother.

Alright, now on to you. One of Two things you should think about. One is tell her you want to spice things up. WITHOUT the 3rd person ok. THEN if that's not even enough, STOP watching po*n.

Po*n is the main reason why men, like me and you feel like sex is boring at times, but here's the thing man. You Fiance, mind as well call her your wife. You wife, and you have been with each other for 6 years. That's longer than my relationship with the ARMY. Damn I'm tired of being here. So anyways. Love her, nurture her.

You might never find true love ever again. Love is more than just sex. You might find somebody who's tighter or wilder, but those needs, will never be fulfilled. It's not her that's not giving you want you want. What you want will not be achieved.

However if she just don't want to have sex at ALL. Then DAMN, tell her you want to spice it up man. F wrong with you.

You have two options, and only two options.  Option One is to get the hell out and hope you can find someone more suited to your personal sex drive.  Option Two is to marry her and find out that all those jokes about married women are actually true stories.

Since it might be relevant to your current situation, lemmy give you my personal testimony.  I was a total male schlutt in high school, the guy who never missed an opportunity to get laid.  Hot girls, geek girls, artsy girls, rocker girls, even ugly girls weren't a problem for me.  Let's be honest, girls are only ugly when they're dressed and standing up.  I played in a rock band for years, and not for the money if you know what I mean.  Then I fell for my best friend, who happened to be a knockout blonde female.

For years, she wanted nothing to do with me romantically.  She was quite frankly disgusted with my sexual history (I did have a rep for dating slutty girls), and only liked me as a friend.  We even took a trip together and shared a hotel room, and I kept my dirty hands to myself the whole time.  But then she started liking me, long after I had given up hope on the idea, and we ended up dating.  Then we ended up married, which is where we've been for just over 21 years and 3 kids.

Before we got together, she was a virgin.  She was still a virgin until almost the 3-year mark of dating, in fact.  I cured her of her virginity, and she really liked sex.  Even after we got married, she still liked sex.  She liked sex right up until she decided she was done having kids, then her sex drive shrivelled up and died instantly.  The last time I had sex was January.  January 2019.

Learn from my mistakes.  I beg you.  

If it is going downhill now it is just going to get worse.  So your choice comes down to making you happy or making her happy.  If you pick you then end it now.  If you pick making her happy be prepared for keeping your sex life well in hand.

You need to be honest and tell her the truth about how you feel that you need her to participate more. But if your desire to sleep with other people is too strong then maybe you're not ready to be married on the other hand you said you would be content if it was just her. Listen to the second feeling you obviously care about her but not communicating how you feel with her is gonna light the fuse the dynamite that's gonna blow up in your face if you don't nip this communication issue in the bud. Take care of it before it gets out of control.

Do you want more sex with your fiance' or are you starting to get cold feet because of the upcoming wedding..? Are you starting to realize once you're married this is it sexually speaking..? Because when you say you want sex with other people,that's not really saying that you wish you could be with her more. That's leaving her out of the picture altogether. 

And when you answer this, you need to be honest with yourself so you can eventually be honest with her. Being honest is better than lying,even by omission down the line and marrying when you're not ready. Or having serious doubts about her. Doubts about needs being met and your ability to stay faithful within a marriage.  

You need to think about what you want and decide. IF you decide to stay and marry her,you both need to have an honest conversation about sex and expectations as soon as possible. I also highly,highly recommend pre-marriage counseling! They can teach you both on how to talk to each other,especially when it comes to difficult topics. 

You let her go and find someone else or play the field. You DON'T marry this girl and end up breaking her heart when she catches you cheating on her. You aren't ready for marriage. Let her find someone else. You need to think of her and let her go.