No advice on tt'ing from me as am not there yet - but just wanted to say that my 4 year old nephew will still deny needing to go the toilet even though he's holding his willy and clearly busting if he's in the middle of a movie or activity of some kind and my mum still has to nag him when he's here to go through the day so he doesn't hold on until it is too late - I think that's standard and not a sign of not being ready so much as not wanting to interrupt what doing. Sounds like you're both doing great though, well done.