My husband and I got married at very young ages and things are beginning to fizzle. Our kids are getting older, work is demanding and it seems like we don't have the same interests any more. After many years of staying home I decided to get a job out of the house and I am loving it. My boss who is also maarried and has been having a rocky marriage has been flirting with me and I thought that this might lead to something. I am usually able to joke with him but the other day he asked me to stay a couple extra hours longer and my reply was I can't unless I go home and sign the divorce papers and give him the bill. I said this because part of the reason my husband and I have been fighting is because of the long hours I work. Boss said that I was starting to scare him. Today my husband called to yell at me while I was at work. I told my boss what happened and he automatically started shaking his head and sided with my husband by saying, "Well there is always something," and then on to say how much my husband must love me. He is trying to stay his distance now. Why? Until now he has been a non stop flirt. Did I screw something up? What can I do to get his attention again? He is such a fun loving tender man compared o my husband and I want to pursue this.

From the bosses perspective what I am reading from what you wrote.
A. my reply was I can't unless I go home and sign the divorce papers and give him the bill.
Boss said you are starting to scare him.
Translation: It sounds to the boss like you are interested in more than flirting and he wants NOTHING more than the flirtation level.

B. I told my boss what happened and he automatically started shaking his head and sided with my husband by saying, "Well there is always something,"
Translation:
Too much drama for your boss. He doesn't want your problems because he has no real interest in you other than doing your work.

C. and then on to say how much my husband must love me.
Translation:
Trying to take your interest back off him and put your focus back on seeing that your husband is the one that has the love for you NOT your boss.

Bottom line: Your boss is doing NOTHING more than flirting with you and has NO interest in you beyond that. He is happily married but flirts to boost his ego and in his mind he may even use the male mentality that says flirting with a woman gives her something to feel good about and boost your self- confidence level. Yeah that is exactly the way guys think. Too many have told me that is the only reason they flirt. If he wanted more than that he would have taken it to more levels than flirting.
Has he bought you flowers, candy, personal presents for absolutely no reason? Has he taken you out to a romantic dinner? Has he taken you to a motel room?
Even then that still isn't necessarily proving anything more than using you.
Your comments are scaring him off because he sees you read more into it than simple flirting.
You need to stop flirting with him and just do your job and work things out with your husband. Your marriage can very likely be repaired if you put your efforts into putting the spark back into it instead of flirting on a dead end street.

To put it bluntly:
There never was any future relationship to go sour!!

There is nothing to pursue, as your boss has no romantic interests in you. You got really carried away by some office flirting and he is backing off.

You really need to take the hint, as your boss is taking your husband's side in all this, so take a look at yourself, and if you truly don't want to be married, do something to change it, not look for someone to cheat with.

Keep pushing the boss and he may fire you. I would.