Although I've described my situation in various threads, I was not posting here before reaching Piecing. My H never physically left home--he arranged to be in another city "on business" during the week, and then on weekends he'd try to sleep on the couch/go out on long errands, etc, to avoid interactions with his children and myself. (He'd been a great hands-on dad previously.) When he did interact, he really wasn't "there"--he sometimes tried, but his depression put him in a completely different headspace where connection wasn't possible.
Some of it he described to me later--above all, that intense need to escape; sometimes he'd fantasize about driving into a tree and ending it all. He would often ask, "Why did this have to happen to ME?" suggesting he felt like a complete victim.
For the 2 years before he met the OW, I believe he spent his time in the other city going to car and motorcycle shows, going to "younger" bars and restaurants with co-workers (he suddenly drank more), sometimes just driving aimlessly about, listening to younger music and shopping for younger clothes, and making new online friends who shared his interests.
After he met OW, she became his focus, and he spent hours texting/calling her daily. At home, he'd spend hours in the dark playing a song on the piano that it turned out he'd composed about rescuing her from her crappy life. He also threw himself into his work to give his life some worth, I believe.
There have been some post-MLC posters here who've shared what was going on in their heads. One was Butterflymom's husband, FavoriteWierdo. Another had several names, all beginning with Happy (HappyAgain?). The glimpse into his MLC mind was pretty strong stuff: even coming out of the tunnel he was quite vitriolic.
You might be able to search for them among the resourced threads. Also, every year somebody revives them and posts some links--you might check for those, or ask if anyone knows how to access them easily.
