According to a couple of private investigators who can spot a cheater like it's their job — because it is.  Here are telltale signs that a woman is cheating on you.

1. She doesn't want foreplay anymore.
Quickies here and there are great, but if she's always eager to get started, something is up. After all, few women can really get into sex without foreplay. So a woman who consistently just wants to cut to the chase probably means one thing: "She just wants to get sex over with". Well … sex with you, anyway.

2. She tells you even more than usual about her day …
If you were cheating, you might be even more vague than usual about your day-to-day schedule. Well, women tend to take the opposite approach: They try to cover up their tracks by sharing even more information than normal. "She'll tell you lots of details about her day so you won't wonder what she's been up to and get suspicious". Of course, she's leaving certain things out.

3. … while rifling through her bag.
Body language can tip you off to a cheater.  If she puts her hands in her pockets, touches her face, or pokes around in her purse for something, it's a dead giveaway that she's pulling one over on you. "They're all signs of nervousness".

4. She stops texting as much.
At first you may not even notice when she starts to lay off the Blackberry — but when you do, it may be time to worry. "Women who text a lot don't just suddenly stop". The more likely scenario: Her thumbs are still getting plenty of exercise, but not when you're around since she doesn't want you to ask who's on the receiving end of all those texts.

5. You never feel as though she's nagging you.
A woman who doesn't mind raised toilet seats and has no issue with prominently displayed Star Wars paraphernalia? Sounds like a keeper. But if those things used to bother her and don't anymore, it may be because she no longer has any intention of keeping you. "When she stops nagging, it means she doesn't care about the relationship anymore".