This is turning into a very interesting discussion, which I had hoped it would, and the results were kind of predictable in that it is certainly a personal decision about feeling adulterous.
I to don't like lying to my wife but other than that I don't feel like I am committing adultery. My lie was where I was for a 5 hour period out of our entire marriage of 40 years plus. As I am doing now, I know a person can justify it anyway they wish but there really are many extenuating circumstances.
While it is never right nor advisable to lie to one's spouse or partner, sometimes it may be best to leave a lot of things unsaid. In my case I know my wife has no interest in my BDSM desires. Yes, we used to discuss it. I also know that if she did find out that I visited a professional to fulfill these desires, she would forgive me my discretions. She would not understand them but our love is great enough that it would not be destroyed. I went once, enjoyed it, but probably will never go again. It took 63 years to do it the first time.
It is also possible, for me at least at my age, that I now feel that I have experienced what I had always fantasized about and now my curiosity is satisfied. I made a conscientious decision to visit but had I thought it would jeopardize my marriage, I would have forgone it. I'm still very interested but will control those feelings as I have always done in the past. That is another reason I like this forum so much because all subjects can be discussed with no judgments passed.
I lust in my heart but I do not commit adultery, by my way of thinking.