I don't know what to make of this...
As for the thing about Felix Sr. being gay; that was addressed some time back as a rumor when Greg King found an some documents or articles which disclosed newly discovered information at that time that had named a young man as one of Felix Sr's 'favorites'. It basically stated that Felix Sr. preferred the company of men , and one has to remember that Felix Jr. wrote how his father wouldn't travel anywhere without his selected group of friends. This information made many wonder why it was that Felix Sr had been so mean and cruel to his son Felix Jr when appearently he was out doing the same. It would seem to me that the logical answer to that question would have been that Felix Sr. would have been the 'old' school type which did things "in secret" where everyone knew but didn't say anything, however Felix Jr did everything in such a flamboyant way that it made his father angry, shocked and maybe even disgusted by his son's actions.
Back to the actual topic...
Many woman of nobility turned a blind eye to their husbands affairs, could it be possible that Zenaida simply choose to do the same??? Or could she have been kept in the dark about it?? I hardly think she would have been pleased to know that a son from her husbands affair was named Nicholas, when the death of her own son was still an open wound.
I don't believe Felix Sr. would have been able to maintain anyone after the revolution. Like Annie stated, it's hardly believable that Zenaida would have sold her precious collection to support her husband's mistress. Felix would have had to have set his mistress up with a large fund before the revolution which would have allowed her to live in comfort. I for one believe that it's very possible Felix Sr had a mistress but don't believe he financially supported the family after the revolution. It would have been pretty low to use the money your wife recieved from the sale of her jewlery to support your mistress and the family you formed with her, pretty low indeed... somehow I'm also coming off a little offended for Princess Zenaida