Fair enough question. I did not, as you proposed, cheat to fulfill anything but physical needs. I never became emotionally involved with anyone or had any 'relationship' with anyone else.<p>
Before I met my wife, I had an active and varied sex life. When we got together, things were pretty exciting and 'creative', but after the kids came, she cooled off and exhibited less and less interest in sex. She had switched into the "mommy mode", a non-sexual view of herself which is not uncommon in child-raising women. I tried to initiate sex, and tried to be sensitive to her needs (or lack thereof). I resorted to masturbation a lot, to blow off steam (and other stuff!). I suggested she go to the doctor for a hormone panel, which she did and everything was fine. I tried pleasuring her in more calm ways - massage, caressing, etc., to bring her libido up to speed. Not too often did it awaken her desires. I felt like I needed/wanted sex and she did not.<p>
But the urge was too strong to have truly fulfilling and frequent sex, and it was easy and discreet to find elsewhere. Once I'd "crossed the line", there was no going back and I actually let some of the pressure off of my wife (which she seemed to appreciate!) because I was getting sexual satisfaction elsewhere. I know it sounds like I rationalizing that my infidelity was to her benefit too, but I'm merely pointing out the way events unfolded.<p>
Up until fairly recently, her sex drive was in a sort of doldrums. Then, my advances seemed to be bearing more fruit...sort of timed with both our kids being able to drive themselves and us having actually privacy in the house. The sex seemed to be more frequent, but still rather traditional, or "vanilla" as some say. So I conjured up this idea in my mind to get us involved in swinging - soft at first, maybe merely dancing, flirting, possibly same-room-sex at the most. Adding some spice, some new experiences, some new, mutual adventures.<p>
At this point, I had sort of lost the need to "cheat" as I was getting sex once a week, or three times a month at least, from my wife. I decided she had somehow shed this cloak of disinterest and now I wanted to nourish this interest of hers. So after maybe almost a year of thinking about it, I "popped the question" to her about swinging....and you all know the rest.<p>
So there you have it - the sordid details....