Hi all, i need some advise. My finance and I have been together for over 2 1/2 years. We have both been divorced once. She works in a male dominated profession as a civil engineer. Before we got together, she has had a male coworker that is a very good friend. They have never been physical, but he definitely has feelings for her. On their last business trip, when several of them were eating out and having a few beers, they were walking back to the hotel. He mentioned to her that she could take her shower for the evening in his room. She laughed it off and called me to tell me. The other day, early in the morning he called her on her cell phone while we were getting ready to go to work. I did not think anything by it as he calls a couple times a week. He has taken a promotion and no longer works out of the same office.
The problem arises when i get a text message on my cell that she meant to send to him. It reads, "Good Morning! Sorry I couldn't talk this morning but C (insert my name) was there. But, anyway, I really do miss you. It was ok when I knew you were just upstairs. Have a good day."

When i confronted her about it, she said that the text was taken out of context. That he had said to her on a message yesterday that he missed seeing her and going to lunch together. She was just saying that she missed having him around too.

Should i believe and continue to trust her? Or am i jusified in my doubts in her and think about ending this.

Please any help would be greatly appreciated.