We've met 4 times...as friends, but I'm really attracted to him? Do you think he just sees me as a friend?

We met months ago and I told him I'd like to be friends and see. We kind of lost touch as his Mom was very ill and he was taking care of her plus has a very busy job. Then I messaged him a couple of weeks ago and he told me he'd like to see me again. He sent me another message 'don't you want to meet up?' as I forgot to reply. Last time we went out was a few days ago. I was showing him photos of a friend's wedding and he looked at me and said 'now we have to get married!' Then he said to me 'don't you want to marry?' I answered 'don't know, I'm alone at the moment (smiling)'. Anyhow I was telling him about the problems in the house I'm in and he said I could stay with him for a night or two if I needed a break. I asked where I'd sleep as he has a one bed apartment (I've been there with him before and he was very respectful). He said 'you can sleep on the living room sofa. Call me and we'll keep in touch. So last night I called, left a voicemail for him to call me when he can and he hasn't got back to me. What do you think? Is he interested or not?