Only you can make that decision. If you take the advise of others, you will have others to blame for their advice. You make that choice, and hope its right, this way you might might make the decision best for yourself.
When I was younger, people weren't so quick to become attached exclusively to one person. It was assumed that, most of the time, young people dated many different people. We used to refer to it as "playing the field." Maybe, even though you love him, you are just not ready for an exclusive arrangement.
"I love my boyfriend, and part of me wants to be with him forever, but ... "
There should be no "but" in the equation here. Love is all or nothing, it really is that simple (or 'that complicated' if you care to view it this way instead.) There is a part of you that you are witholding from your boyfriend; you can't give him your all whilst giving a part of your feelings to someone else; love doesn't work like that, or at least it can never fully work like that.
You need to sit and think. If you love your boyfriend, then he *should* have *all* of you. If you are not prepared to give him your all, then you need to consider the depth of love that you have for him and if he *really* is the one that you give your eveything to.
You cannot have it both ways; it isn't fair to anyone (including yourself) withold your feelings if you feel you are falling for someone else. You really need to sit and think this through.
so i think you know that that wont work out you have to find search for yourself which one feels better for you i guess completes you so to speak you cant want you cake and eat it too its not possible cause i can guarentee you if you decide to keep two it will be fun for awhile until youll be getting tired of covering up your tracks trying to remember your lies etc until you will get caught now that wouldnt be worth losing one of them in that way so be honest and see for yourself which one feels right for you and tell the other one it cant work out or just be friends friends that dont have sex haha ask yourself what would you do if it were him in that situation what would you do if you found out youre not the only one and he has to choose you wouldnt feel great right