How do you interpret this guy's behaviour?

(Live outside the UK)

Went on three dates with a guy, both obviously keen on each other. Excited et cetera. My understanding is that this guy isn't over his ex yet, despite breaking up in April, apparently they still saw each other. I was the first date he'd been on since.

We had a fourth date planned. He cancelled and said I was lovely and he really enjoyed his time with me etc. But now is not the right time for him. He said he'd love to get to know me some more in future, but for now he's calling it a day.

I responded that I understood how he felt, but if he wanted to date me, it was now or never. (Sorry but why am I going to hang around?)

He replied that he would react in the same way so he gets it, but for now he thinks it's best where we leave things.

I wished him well and left it at that. I probably should have been nicer but I was sad that something I thought might go somewhere ended.

What are your opinions? Do you think his ex came back into the scene? Do you think he genuinely needs more time to move on?

Was his way of saying that he doesn't want to see me now, but would definitely want to in the future, just a nice way of saying he's not into me?

I don't know whether to give him the benefit of the doubt