Married for 10 years?

She needs extra attention on the bed...maybe the idea of threesome may spark her life but unfortunately it has to be a man...if you want to see her happy you got to take off your clothes with another guy presence with your wife so both of you can do a team work and nail her well 

This comes under the category of "What the...?" WHY would any married woman declare she is single, say "I love you" to strangers on the Internet UNLESS she is looking to A> cheat and/or B> Get out of the marriage.

You have every right, as her spouse, to challenge this behaviour. Of course she gets defensive - she KNOWS it is wrong, but doesn't want to stop it.

Suggest either counseling to get to the root of her issues, or seeing a divorce Lawyer - cause I have a feeling you ARE going to need one in the very near future.

It sounds like your wive is not happy in the marriage or satisfied. Please have a serious talk with her. Do not waste anymore of your precious time with a person who does not want to be joined in a union with you. You deserve someone who will be faithful and respect you as a man and a husband. If she is telling guys she love them on the phone she is pretty much in a relationship with another man or men and possibly having sex with them as well. 

She's cheating. You sound like you've already done some detective work, the best thing to do now, is confront her about it. But, once the trust has been broken, it's hard to go back to normal. You'll always be wondering in the back of your mind, if she's sneaking around, and with whom.