KiwiAmanda - sounds like you've been really hurt in the past
.
I am reeling slightly at the vehemence of your opinion - but I think the crucial point you raise is your last one - COMMUNICATE, COMMUNICATE, COMMUNICATE.
If communication completely breaks down between a couple (in conjunction with dishonesty with oneself and with one's partner) then the relationship needs either to be completely readdressed and all of the offending issues identified and addressed mutually with residual blame or resentment, OR, the relationship is actually a sham and it is only fair to to be honest with your partner and GET OUT before you break hearts and confuse your children.
Children pick up changes in us far more than we are likely to admit. They will KNOW when things aren't right (or different) and their behaviour will almost definitely start to reflect this.
I know. I made this mistake. Step 1 - be honest with yourself and conduct yourself with integrity. Step 2 - act accordingly. Step 3 - be honest in all of your relationships.
That way, you can face the consequences with your head held high. Sue Atkins of Positive Parents recently suggested that "Imagine looking back on this period of your life when you're in your rocking chair at 90. What are your memories? Did you conduct yourself in a way that you can now defend and feel proud of?" (paraphrased by me).
If you can, then you are acting with dignity, respect and integrity. If you can't, then something's got to give....!