If Su Ming wanted to give Deadpool a house, Deadpool would have happily started packing to move. Why would there be so much trouble?
But The Flash's refusal was within expectations too. He was that kind of good person. It might be a stretch to say he devoted himself entirely to benefiting others without any thought for himself, and he was nowhere near as saintly as Superman, but Barry truly disliked having financial dealings with friends. That was his principle.
Superman was not so strict about such things. Back when the farm in his hometown had nearly been seized by bankers, Batwoman bought the bank, preventing Superman's elderly mother from being forced out of her home.
Superman had been deeply grateful for that and had not refused his teammate's kindness. Buying a bank was no small expense, after all.
As for Barry, at most he ate subsidized meals at the Hall of Justice. He never took advantage of anyone in other matters, and he never borrowed money from his teammates, whether it was Batwoman or wealthy people like Green Arrow.
Su Ming could understand that as well. Honest people were like this. Borrowing money from others made them uneasy, while accepting expensive gifts from friends made them feel embarrassed.
But in truth, a house was nothing. Given The Flash's value, even giving him a Single Universe would not have been a big deal.
"Looks like you understand what I mean. Then it's happily settled. Come on, let's go look at houses, and then I'll buy you one." As he spoke, Deathstroke's armor squirmed and reshaped itself into the form of a suit.
Seeing that The Flash was too weak to refuse, he smiled and pulled him along, ready to go house-hunting in the middle of the night.
"Wait, Slade. Didn't