Please help me guys. What do you think? Is my man cheating on me?

[confusedisme1]

Ok, So my partner and I have been together for 8 years and have a family together.
There has been some pretty crappy stuff go on lately and im not sure what to do.
I went on to his Facebook to see a message from a girl at his work who is Married with no kids.

She wrote a message saying " I would love to kiss you" and "dont you see how i look at you at work".

I was so angry and spoke to my partner who claims he knows nothing about and that he had given his log in details to another guy at work and that the message was for him? Believable?

I let that go and believed him.

I than found him sitting in HER car at an oval around the corner from out house at 2:30am. He apologized for this and said he was in the wrong and i had every right to be angry but nothing happened. He said they parked there because he was hoping i would fall asleep and not see her drop him home??
Since than, he deletes messages he has with her at work daily. He says they are for work but who knows hey?

The last 3 weekends he has made contact with her..... He says the last messages was he asked if she was having fun at a party. I dont know what to do or if that is true. . I really dont. Im confused.
He gets a lift home every night from work. A few times over the past two weeks he has been getting dropped off and walking the rest of the way. He reckons that this other guys wife goes to this house around the corner and he walks from there. But how often would they go there seriously? Now that i think of that, i think its a load of crap.
I would really love some advice.
How do i know for sure whats going on? I need to know. I dont want to live in a lie. I also dont want to throw our relationship away if nothing is going on.

Help me please

[searock]

Double post. Original thread here: http://www.loveforum.net/threads/77800-Is-he-cheating-on-me?