We had a simlar problemw ith Coby, he wouldnt go to bed untill 9 or 10ish and that would be him falling asleep down stiars either on the sofa or on our laps, we tried teh crying thing but i couldnt do it, walking away and hearing him scream but broke me.
In the end i had to be strong in order for me and JAse to have any time alone together, but instead of leaving him i laid on his bed with him.
For the first few nights he tried to get out of bed, i would just lay him back down and say bedtime really firmly, he would cry and shout but at least i was there with him, i didnt speak to him, just put my hand on his back to let him know i was there, after a while he soon gave up and laid down then went to sleep after 30 mins.
We kept doing that each night without fail. now we take him up to bed at 8, lay with him and we are back down having dinner together by 8.30, Coby doesnt cry, he knows now that its bedtime and thats it.
He was older then Rhys when we started doing it so it might have been easier to do, but keep at it, it will pay off in the end
x