I'm going to be a bit contrarian
I'm a big fan of sex columnist Dan Savage. I think Deanna would be well served by reading some of his columns on the issues of infidelity (or listening to his podcasts).
I think we all are in agreement the cross dressing and the sex outside of marriage are two different issues; one does not cause the other.
It's possible the husband is bi, and not gay. However, the additional information about no sex for 10 years suggests he is gay.
Savage talks about compassionate marriage, where the married partners live together because of love, but have sex with others. He also discusses having sex outside of marriage so that the person who is "cheating" can stay same.
The percentage of people who have sex with individuals other than their spouses (i.e., cheating) is very high. Not all of these episodes lead to divorce. Probably every one on these boards knows someone who has an affair but the partners put it behind them and stay married.
As to finding condoms, yes, it indicates sex, but would it have been better to have unprotected sex???? Isn't the husband being responsible?
In fact, the husband could have been a better husband because he was having sex outside the marriage; it is certainly possible. Especially if the couple hadn't had sex for 10 years.
The question has to be, was Deanna happy with her life for the past 10 to 15 years while her husband was living his secret life? If the answer is yes, then why does the marriage need to end?
None of us can answer these questions; only Deanna and her husband can. But as I wrote above, Dan Savage has talked a lot about these issues, and I would encourage Deanna to read some of his thoughts on these types of issues.