So, then, today's story begins when Zong is returning from a good-will "mission" at the coast of the Fire Nation helping the mid to lower class people rebuild after a storm had knocked out their houses. He was supposed to have finished and been home by noon, that day, but Azula got news that he was behind schedule and should be back the next morning, instead. Naturally, Lady Azula felt the need to express her discontent towards the first born less favored son, informing Jhao (and Suki) and the Fire Lord of his delay. From there, he finished sooner than he thought and hurried home to see Yue.
Jhao, knowing that his brother would not be back that day but instead in the morning, and knowing that Yue (the commoner daughter of her once-enemies from the Watertribe who married into the royal family through the son she rarely acknowledged) was still expecting her husband home early that afternoon, decided to play the part as evening closed in on them. (He didn't say anything to Suki except that he was headed out.) He did his best to act as Zong would (and through repeated attempts and gauging her responses he'd become fairly convincing) and fell asleep with her in his arms as the last bit of daylight left the sky.
Then Zong got home. He headed for their bedroom expecting to find Yue alone. But he did not. Hence he returned to the palace gardens and perched in the Zuko-Conception tree (ZOMG, Twin Lieu conception, MEBBE?! ... Or mebbe not...? Oo) until very late that night (midnight-ish) when Jhao crossed through the gardens to return to his own wing of the palace, his own bedroom, and his own wife. Zong was still quite awake. And pissed.