SladeBruce (DeathBat) Analysis
The Wife: Bruce Wayne (Batman)
When Deathstroke figured out Wayne was Batman, it was strange but made sense thinking on it. Finding out all the Robins were Wayne's children was just pure gold because of the irony. During the night when Deathstroke faced off against Batman, he enjoyed the fights and aimed to make him bleed but during the day when Bruce was only around, Slade found comfort in being among the pretty boy billionaire. Knowing now the personality was a facade made Bruce far more precious to him. His dynamic with Bruce was a symbiotic relationship of patience and restraint.
Bruce tolerates Slade being in close range and made it clear day one that he would attack if Slade did anything rash. But they learned to trust one another enough to fool Gotham into thinking Wayne had a suitor. It kind of turned into reality when there were plenty of likenesses between them. What Bruce didn't like admitting was he enjoyed the presence of his greatest foe because he reminded him who he really was outside the walls of Wayne Manor and the oblivious city. The Robins obviously hate Slade but they can't exactly tell their father who to date. While Bruce plays the arrogant rich boy publicly, he's laid back and serious in real time though he acts like the reasonable authorative figure between the two.
Out as Deathstroke, Slade tests boundaries and for good fun. He's the fun parent to a degree. He wants to see what Batman will do when he taunts Wayne if the latter has nothing holding him back. He will get Bruce to chase him across Gotham as much as it takes to break him. In rare times, Slade will help Batman take out large groups of thugs as his version of a courting ritual. It works as well as you think. When bored, he has a tendency to show off to Bruce like balancing on his staff and exercising his weapons. Bruce shows minimal acknowledgement of the feats but secretly likes the showmanship.