Unlike popular belief relationships are built on honesty not trust. People will wit Houten a doubt mess up sometimes, that just is how life works. You can't expect them to be perfect so you can't blindly trust them. If you get suspicious it is important for you to _honestly_ express those concerns instead of just brushing it off and saying "I trust him/her" and it is likewise just as important for the other person to _honestly_ address those concerns. Also any time something is wrong with the relationship, you are developing feelings for someone else, you do not feel there is enough communication, y'all aren't hanging out enough, etc. It is vital that you honestly tell them this as soon as possible or it will never get resolved and build into a larger problem later down the road.
I am not saying that you should always be going all crazy-stalker on your significant other or that you shouldn't take them at their word, I am saying that building a relationship around "trust" will cause a lot of things to go on without being addressed because they feel they have to blindly trust their partner.
Not to mention almost every time I've seen a case of someone cheating the perpetrator will constantly say things like "you need to trust me more", "why don't you trust me?", "trust is the most important thing in a relationship so you need to just trust me" instead of answering the question.
COMMUNICATION. No exceptions. It is beyond me how anyone can stay together without communication... So many people are on this site asking "does my boyfriend want to break up with me?" And "what do you think my boyfriend is thinking about ___" when that should be a normal part of communication...
"Communication." -- People who've been stonewalled
"Honesty." -- People who've been lied to
"Fidelity." -- People who've been cheated on
"Excitement." -- People who've been bored to death
You see where I goes with this.
At best, this question is deceptive. At worst, it's meaningless. EVERYTHING is important -- but most decent relationships have most of the things. Really, this question is just about what COMES TO CONSCIOUS MIND when the question is asked. And that's more of a "personal history" thing than a "relationship priorities" thing.
Trust, because trust is the foundation for every relationship. Without trust the relationship will never be a happy one and won't last. I couldn't stay with someone who I couldn't trust, ir if they betrayed my trust.. in anyway at all
An open stream of communication (open also implies honest, but also not withdrawn, not cold, not distant).
To me a clear sign that a relationship is going really foul in this regard is if one of the two partners needs to say something like, "We need to talk", as though an appointment is needed to talk openly about a difficult subject.
Lovers should be able to talk intimately and share their feelings about everything. That's the key, as I see it, for a long-lasting relationship. Women usually have it easy here to communicate their feelings.
Men don't so much. A man confronted to share what's troubling him might get angry and want to distance himself away from the situation. The way I see it is like boxing -- this is equivalent to stepping back from a punch and it's the wrong move. You have to go against your instincts and embrace the partner and tell her what's bothering you, e. g.
Mostly I see this as key. Whenever I see a couple growing distant from each other, it's because they can't talk openly to each other. You see the problem a lot on this site where some random girl or guy is asking internet strangers for advice on how to tell their partner their feelings, when they shouldn't need our help to do it.