Wow, you and I might know this same person as the circumstances sound identical. This happened around 2001 up in Dallas area.
Even though I was not happy (personally) over the choices he made, I'm still his friend. Doing what he did came with a HUGE price as he has children as well.
There are times where he eludes to thinking it would have been better had he kept everything in the closet because even though his SO (on the outside) was saying that she was accepting of his (then) behavior, she was telling my SO a completely different story. When he decided it was time to be all he/she could be, his marriage was essentially over.
It was an awful time watching that train wreck happening, but we still gave them both as much support as was possible.
*Much hugs*
Zara