How should I really take this, good or bad?

Ok, so I am going out with an older man, he is 16 years older than me (I am 30 & he is 46), He is divorced no children,was married for 10 years ,we get along really well,and he treats me super nice,he is a gentleman and much more,we don’t have a lot of time of being together,yet we feel so close.The point is that yesterday we were together and he was supposed to come pick me up at 4:00 pm but he came at 5, due to the fact he was looking at some apartments, when he finally came and picked me up, he was telling me all about it, then later at night he showed me the pictures of the apartment, it was a woman who was showing him the apartments and giving him all the details. he wanted to rent this apartment with her so both of them pay half of the rent and the third room they both would rent to someone else.

so he was showing me the conversation with this woman, and this woman had send him one last text that said:”what r you doing”? an he replied in front of me ”I am with my girlfriend watching a movie”,and also this this woman had told him can you send me a picture of you (this was before they had even met to go and see the 2 apartments) so they both send each other pictures I guess to recognize themselves, I don’t know.

So know I am wondering is there something going on in all of this? or maybe this girl felt attracted to him, and wanted to go out with him? or is he up to something with this woman. I feel he has been really nice with me, and this also scares me in a way, I mean is it normal that a man is always super nice, taking a girl to restaurants and treating her like a princess so FAST!! what are your thoughts! or behind all this nice,sweet gentleman there is something else he is trying to hide?