Do I buy a house? What about sex?

[Trixi]

Hey all-
I have been on and off this board for years now. I will try to keep it as brief as possible because I REALLY need advice ASAP.
Me:40
WH:44
Married: 10 years on July 26th
DD:19
DS:20 Both children living on their own.
No affairs (Well, he had a brief online thing end of 2004)

Current sitch:
He has been ambivalent about "us" for a couple years. Actually, he had planned to divorce me in 2006 (unbeknownst to me). I found out his intentions late 2005 during a discussion. I did everything I could to be a good wife. Lost a lot of weight. Tried to meet his needs, etc. So, the ambivalence regarding "us" is due to me making changes that made it hard for him to actually divorce.

He has been really a poo-head lately. Continued to say he didn't know if he wanted to be married, etc. Refused to actually put in the time to build up love feelings. Started playing guitar and writing music and now he wants to "pursue" his music.

Finally, last week I couldn't take it anymore and I pressured him for an answer. He picked splitting up.

Our initial options were:
1-He rent an apartment and rent furniture and clear his head.
2-I rent from my parents.
-I go and buy a house.

At first he was going to be the one to leave. Then he decided that I should go and buy a house. Reason: he doesn't want to "lead me on" by doing a trial separation, because he doesn't think he will change his mind. I pointed out that reversing the purchase of a house (should he change his mind) is expensive, and he said that *if* he did change his mind and we lost some money-so what? it's only money. The important thing would be that we would both KNOW that he REALLY wanted to be with me and our relationship would be WAY better than it ever has been.......But, he didn't see himself changing his mind....but maybe he would...but he didn't think so...but who knows, he can't read the future....he might realize that he really misses me. (these are all words out of his mouth)

Since he "made up his mind" I asked him to sleep on the couch. Then yesterday we were hanging out and I made the mistake of falling for an afternoon "booty call". It was a great time, darn it! That evening I told him that he could move back to the bed if he wanted and he did. (STUPID ME)

This morning it was awkward between us. I can tell that I made a HUGE mistake. I am going to set up the spare room for him to move into tonight.

Question:
Buy a house?
What about the sex?