Thanks for your reply Anthony. Just so you know, his second child had already been born.
Marina testified to the following about Lee asking her to move with him into an apartment:
Mrs. OSWALD. I said [to Lee that] it would be better if I remained with Ruth until the holidays, he would come, and we would all meet together. That this was better because while he was living alone and I stayed with Ruth, we were spending less money. And I told him to buy me a washing machine, because two children it became too difficult to wash by hand.
Mr. RANKIN. What did he say to that?
Mrs. OSWALD. He said he would buy me a washing machine.
Marina also said (I can't find the source to cite it) that he told her he was going to stay with her at the Paine residence that weekend but not Friday night because he had visited on Thursday.
There was nothing - from Marina's point of view - indicating their marriage was over. As she said above, she was hoping they would all get together for the holidays. Perhaps he thought differently.
And, of course, nowhere in his interrogation with the police did he mention a breakup with Marina as the cause for him going to the movies; which, apparently he sneaked into despite having about $18 on him.
It's possible but this is speculation based on, as far as I can see, no evidence whatsoever.
And oh yeah, why did he go to the movies?: He was escaping from the police because he had just shot one of their officers. Question: I've been outside when police cars went screaming by. I stood and stared at them and wondered what the hell was going on? Oswald apparently wasn't interested in all of that commotion. Why?
Marina's testimony on the above is here:
http://mcadams.posc.mu.edu/russ/testimony/oswald_m1.htm