I've just said, 'it would be great to go out for a meal tonight. I've seen this restaurant it would be good to try. I'm going to go at about 6pm and it would be great if you would join me. If you don't want to, that's fine, I'll take a book.' I said it in a nice tone and smiling - not passive aggressive or grumpy.
Unfortunately, I think youre still too big. Going out, spending money on alone time for an hour or two is a lot of pressure (somehow....). Its clear he doesnt want to spend a ton of time with you talking or doing things. So, Id try to avoid the long commitments like a dinner out.
I would start by saying "thank you" or "I appreciate ___" or make a snack for him.....Im not sure exactly. But start by doing something small. Consistently. for a few days. see what changes that imparts. Then add a new thing. Or change that thing. And keep repeating.
