

Explain your situation then.
Sounds to me like you love your partner and they love you. You’d like to leave to go have other life experiences.
It’s pretty easy, which do you value more, the love you have for your partner or these life experiences you could have?
I don’t know you, but my guess is that if you are thinking about it enough to want to find an answer, then you already have your answer. You value the life experiences more, you care about your partner, and you don’t want to hurt them.
I’ve been married to my wife for over a decade now, I love her with all my heart, I can’t think of any kind of life experience that would make me want to leave her. I imagine that love is not a binary on or off type thing that there are degrees and kinds of love. It’s very well possible that you love your partner but not enough to want to stay together forever.
This is really a question that only you can answer. Which do you want to do, it’s your one life, you get to choose. But don’t stay with your partner because you are afraid of hurting them because if that’s why you stay, you will become bitter and resentful and the idea of “what could of been” will always be this perfect thing that they kept from you.
Stay because you want to stay or leave because you’d rather leave.
If I were your partner, although it might not feel like it in the moment, the sooner the better.
If you aren’t going to commit to them, that’s your choice to make, but free them up to find someone that will. Every ounce of love and time and attention they pay you from the moment you make the decision to leave until you find the gumption to do it is a waste for them. The most respectful thing you can do is not waste the precious and finite moments of their life.
Let them know what you’ve decided. Have the courage to tell them plainly and honestly that you are leaving and that you won’t be the person to love them. Let them get over you so they can find the person that will love them.
And don’t you dare double back unless you mean to stay. If you stay do it because it’s what you want not because you feel bad. That partner is a human being, one that deserves the truth and to be loved. If you can’t do that, or don’t want to do that, that’s your choice.
This is the least we owe our partners, to be honest with them, to love them or let them find love elsewhere.
I know you are getting a lot of downvotes. Choosing to leave someone you love is not a popular opinion. I could not do it and I think most couldn’t. In time I suspect you will find one of two things to be true.
This is life though, the hard decisions, and only you get to make them. I hope you make a good one, and above all, if you want to be a decent human being, treat your partner well. If that means standing by their side in love, great. If that means being honest with them so that they can be happy, also fine. Just don’t lie to them, don’t be needlessly mean in ending it, have the courage of your convictions and tell them the plain simple truth. Don’t make up a reason that feels better, don’t blame them for the relationship falling apart, don’t trick them into hating you.
You owe them that at least.