"Women are always screening for proof you're still trustworthy," says Dr Scott Haltzman, co-author of The Secrets of Happily Married Women (John Wiley & Sons, $31.95). Sound harrowing? Not to worry. Here's how to react the next time you trip her trust alarm:

She catches you checking out her hot sister, cousin or friend

This isn't anonymous eye-candy you're "appreciating". The social proximity jacks up the potential for infidelity and, therefore, jealousy.

Say: "I'm sorry. You have absolutely nothing to worry about - there's no-one else I'd rather be with than you."
Be sincere, take ownership of your mistake and keep ironclad blinders on your eyes from now on. She knows you look at other women (she's on guy patrol, too), but wonders why you can't control your impulses. Her peripheral vision will be working overtime.

Don't say: "What are you talking about?"
"Denial makes her feel like you don't understand why she feels bad," says Dr Janice Levine, author of Why Do Fools Fall in Love? (John Wiley and Sons, $32.80).

She learns your pal wasn't always a platonic one

Secrecy adds suspicion of what could happen, says psychologist Patricia Love, co-author of Why Men and Women Talk (Ebury Press, $32.95).

Say: "I wasn't trying the hide it. She's been platonic for so long, I didn't think to mention our past."
Ask her how she'd like you to handle your old flame. Letting her dictate your interactions shows that you put the relationship above the friendship. Invite her next time you hang out with your friend, so she can see how innocuous the friendship is.

Don't say: "There's nothing going on there. I didn't mention it because you'd blow it out of proportion."
She'll think it's a convenient excuse. "It's cowardly and shows you don't trust her," says Levine.

She finds e-mails from your ex

Despite your noble efforts to shield her from the details, her instincts tell her "where there's chemistry and exclusivity, there's the potential for intimacy", explains Love.

Say: "I don't want to get these e-mails any more then you want to read them. Let's figure out what to do together."
Offer to let her read the notes, suggests Love. Then use the opportunity to set the ground rules for how to handle situations like this.

Don't say: "She's insane. Don't worry about it."
This leaves the door ajar. You'd go a little nuts if she kept the lines of communication open with her ex, right? Don't do it to her.

She hears a raunchy story about a bachelor party you'd downplayed

Even if you dodged the stripper all night, your omission makes her worry you may have covered up other parts of that evening.

Say: "Okay, if you want to know, make some popcorn and grab a seat."
Offer up full disclosure if she asks, but chances are she won't. No woman wants to imagine a half-naked dancer gyrating atop her man, but if she's worth your time, she'll get over it.

Don't say: "The strippers? I didn't really pay too much attention."
Now she knows you're lying. Think about Bill Clinton: it wasn't Monica Lewinsky that led to impeachment, it was the lie.