Can you guess what happens when a divorced dad's single spree culminates into a full blown Significant Other? Spending quality time may be enjoyable, but what happens when All's Fair In Love becomes All Out War?

You moved in, you're ready to tie the Gordian knot, and you get along with his kids. Or so you think. But there's that nagging feeling that says you need to slow down because things aren't going the way you'd thought. All your best efforts are thwarted, you realize, because you are experiencing one slight glitch:

"I feel like an intruder," complains Beth, a 30 year old Boston paralegal who moved in six months ago with Ralph, her fiancé of three years. " I have no say in their daily lives, yet I'm a full time chauffer service, nanny, and everything pertaining to their servant. Yet my word means nothing and my authority even less.

I didn't sign on for this!" Then there are the more insidious, covert power issues. "Tom has his kids every weekend, which would be fine except they always want him to participate in sports they know I don't enjoy or cannot do altogether, thereby monopolizing their dad the entire time. When I try to do something with them, they refuse. I tried to talk to Tom about it but he thinks the kids will adjust." Many children, sensitive to the reactions of the new significant other, can use this newfound power against their perceived intruder by extracting the last ounce of attention, including endless demands, inflicting self-injuries, and basically making a nuisance of themselves. Trying to maintain civil relationships with his kids at the expense of your relationships can prove exhausting at the very least, and don't let it surprise you if he uses your relationship with his children to maintain a safe emotional distance from a completely committed relationship. All's fair in love? In this case it's war: 66% of women surveyed said they were tired of this tactic and were seriously considering walking.

"I don't know what I want," muses Michael, a thrice-divorced father of four. "My fiancée is giving me The Ultimatum, but I'm just not ready. I'm under pressure to create a stable environment for my kids instead of shuffling them between their mothers, but it's just too much for me right now." Then he adds, "But I don't like to listen to my fiancée complain about feeling alone in our relationship but the reality is that my kids come first."

The good news is that Michael is honest. Many Not Quite Wives complain about feeling like a third wheel or just being left out all together, in spite of reassurances to the contrary. Constant compromising is common way that many NQW's attempt to earn acceptance, and at a greater expense, love. "I spent the first year of our relationship driving his four kids between their mother in Fresno and back here in Los Angeles," fumes an irate NQW who was "halfway out the door" of her three year relationship. "I was stagnating and really resented the problems, and we fought continuously. Then I realized: I'm trying to micromanage my relationship with them instead of getting to know them as people. Now I understand how this was impeding my progress and I've imposed strict boundaries. Our relationship is so much better."

No two people think alike, and no two people will react alike, even if the situation is similar, which is usually the case in co-parenting arrangements. Many women feel trapped in "forever relationships" with a man who just isn't ready to get to the next base. Everyday issues will come and go, but if you've been battling longer than, say, six months, "you might be headed for disaster," says John Cullen, M.A., a relationship coach in Las Vegas. "If you haven't waded successfully through the turbulent waters of his kids and ex, you need to take the bull by the horns and start somewhere. Begin by addressing pertinent issues that really confound or provoke you. For instance, if you are tired of being the chief chauffer, stop doing it. You need to address the issues, underline them, and begin to define and maintain your boundaries." Boundaries and coping skills are an integral part of juggling volatile emotions and insecure attitudes. "But if you can do this, you'll see miracles happen," says John. It isn't as hard as it seems. Start slowly by respecting the extent of your own patience instead of tormenting yourself with repeated problems. Some good pointers to follow are:

"I refuse to feel powerless," laments Jane, who is into her fourth year as a NQW. Her partner has three children. Jane has none, "and Clark doesn't want anymore." Her partner explains, "I realize my ex and Jane do not get along and I do not want to torment my children by asking her to move in, so if Jane can't accept this, she needs to move on." Another man stoically says, "My ex resents being treated as if she doesn't exist, and the fact is, she is the children's mother, so she indeed exists." Studies show that most men who might remarry do not take the plunge because, as one man puts it, "we're afraid of the constant disagreements between past and present partners." Their fears are not unfounded. Many new partners resist participating in decisions affecting the children, and many resent the monthly bills required to maintain the children's expenses. "My fiancée was jealous because I spent so much money on my daughter's parochial education," sighs Chet. I finally got so disgusted that, after two years of it, I told her to hit the road." Confrontations may become inevitable as families becoming realigned will begin to include the NQW. Along with her new role, the NQW can feel some semblance of satisfaction within the family infrastructure. "As long as they've come this far, they can pretty much expect to make it together," says John. "With time and commitment, they can dismiss the baggage and move forward."