Why won’t he just be open with his kids about us?
woes. I don’t think it’s that he’s being selfish but maybe he’s just overthinking things and worrying unnecessarily. He’s assuming his kids will take the news badly but, actually, they might be fine about it and even pleased that he has someone special in his life again.
He’s been upfront with you, so be upfront with him. If you want more, then tell him you want to take things to the next level and you’d like to discuss how to tell his kids and bring your relationship into the open.
If he’s adamant that’s not an option, then you have to make a decision about whether you’re happy to enjoy his company on a casual, no-strings basis or break all ties and give yourself the opportunity to meet someone else.
You sound sociable and young at heart, so I’m sure you’d have no problem making new connections.