As you and others have already stated, it is a very complicated situation, which does require some deep thinking and longer term decision making on both parts. You are divorced and now are free to do what you want when you want. You have a right to live as you want and should not let a paying housemate (regardless of past involvement) prevent you from being yourself. However, and there are always some "however's", you are in a unique situation that could work for the longer term if you both can find a way to compromise and respect each other along the way.

Do you want to and can you sustain a life in "your" home of continual hiding and sneaking around? Can you live with the constant fear of her eventually finding out? Is this side of you important enough to make it part of your true, safe and private everyday life within your own home? If the hiding, sneaking around, fear of being caught and just the overall inconvenience of doing all that and risking your own sanity and emotional well being, which may change you to someone you do not like, then my recommendation is to deal with it now, openly and honestly with her. You have a chance to be totally honest with her and yourself that will be better for your, and her, long term health and sanity. Why go into a dark unknown situation when you can make and keep your life healthy by staying away from that?

As with any decision that we make, there are risks, one important one in coming out to her is that of a bad negative reaction on her part, which could cause some very deep pain, inconveniences and suffering in your life as you try to get back to a workable normal for you. You know her better than we do, even though I believe that in most typical relationships we do not know our partner as much as we would like to. Also, as with any type of decision, it is yours to make and not us in the peanut gallery of this site. If you need help, or courage, read some more here, dig deeper into some replies that may seem workable to you, and if necessary, seek third party support to help you with the relationship side of all this, assuming you are comfortable with who you are today.

And, as always, I do wish you the best of luck in all this.