Good to "see" you Snufkin. Congratulations on passing the one year sober mark!
If I were you I would be hurt that he did not tell you he had a child in a year of being together. Fair enough not mentioning it on a first date but once you are in a serious relationship you cannot have secrets like that. Also he says he wants to "inspire" her to be a better person than her mother but presumably he has not had any contact with her so he is in no position to say things like that. Even if his ex did cheat on him that is not his daughter's fault. For those reasons I don't think there will be too much drama over his daughter - if he really wanted to see her he would have done so by now.
In my opinion the real issue is how you feel about his lack of openness about something so fundamental. I would ask him why he didn't tell you and then see how you feel about things after he has given you his reply.
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This is just my opinion jr but Spiral is right up there with The Wire, The Soprano's, Breaking Bad or The Bridge. There are lots of seasons of it too.
Here is the Aardman clip, as I say it is not their usual style although it starts off that way. Serious stuff.
https://youtu.be/cQB4RAZVMf4