Is Significant Other helping or is there something more than meets the eye?

My better half recently offered to help a co-worker help with a personal problem relating to a computer. The co-worker is not knowlegeable with computers and my better half does this for a living at his primary job. What made me uneasy about this is that they made arrangements for the computer to be dropped off at our home. The person in question showed up with the computer and did not come inside the home. The person was dressed what I consider a little revealing for a manager/subordinate computer drop off. There has been an exchange of personal cell phone #'s and emails during the course of this issue. It was resolved by my sweetie taking the computer to a computer dealer who specializes in computer repair. He set up an account in his own name. A week later the computer was taken back to the manager co-worker. However, there was a matter for him to get the payment for this and I understand from mutual friends that the person involved dropped off a check to my sweetie wearing a suggestive top without anything on under it. I asked my sweetie about that and he swears nothing is going on and he is merely helping out someone who needs help and has no knowledge about computers. I am upset because I was not initially consulted as to whether it was ok for him to do this and then there have been all these little things like inappropriate apparel being worn by the other party during transactions. The plus side if there is one is that though I was not initially consulted, I have been kept apprised of things that were happening. Maybe I am just over reacting, but it seems to me that this person is extending an inviation to my sweetie for something more. When this initially came up, he had mentioned casually that perhaps he'd be called upon to assist with a personal errand for a co-worker but after we discussed it we talked it over and it was decided that he would not get involved. Later the same day I was told that he decided to help because it was important to the person that the PC be up and running due to the data on the pc. I am at wits end over this and so upset that he did not do as he said he would. I view this as a trust issue. Am I really off track? How can I lay this to rest. I view this as I lost and the other person won.