Hi Mr Lee,
I was in the same situation as you, but I'm the wife rather than the husband who falls in love with another girl.
After my second pregnancy, diverting my attention to work, children, home, and maid, I have totally left my husband to survive by himself, thinking that he will, by understanding my situation. I was totally WRONG! and DISSAPOINTED that he does not understand and support me! As he just changed to a new job, with new environment and colleagues, he needs someone to talk to, and I'm not there.
When he's home, I nagged at him, picked on him on small issues, blaming him, and more. After one year, we both blow up when I discovered he's been pretty close with a female colleague, but he denyed any physical contacts.
Divorce was mentioned, but I do not want, as I want my children to grow up in a perfect family. We have a "good" talk, and I changed on my part. Things I do like stay up to wait for him, or accompany him when he works late, spend some time to talk to him (no matter how tired I am), control my emotions, and lots more. I can also see he has changed, more willing to talk about his work... but still his usual self. What more can I ask from a husband...
Mr Lee, we both dated and got married as we love one another. But as times goes by, with work, family, and other responsibilities, we have forgotten to do "small" loving things to show our reassurance, care and concern. We don't talk much, as no time, and the only topics we talk about would be children. And we spend time on weekend with children around. He found another love because he has forgotten his responsibilities, and feels that he's back to his young time.
It is hardwork to maintain a relationship. I actually read a book-Men from Mars, Women from Venus, to understand my situation, as I want my family to stay together. Eventhough, I try to trust him (I used to checked on him, his hp, emails and stuffs), now I don't, as I'm very tired doing it. Work things out with your wife... She will appeciate it.
I'm not in your shoe, or to advice you to leave the gal, but I'm trying to tell you spend more time with your wife(without the children), understand her situation, have a good heart to heart talk.