Feng and Bolin had both been reluctant to join their General's venture outside of the walls without completing the whole month that they were supposed to stay inside. They did not want to leave their families in that instant. They would not be able to say no as he was still the prince but it would be better to leave if it had been their decision.
But it seemed like the general knew of their reluctance for he immediately dropped the bomb that they were not going anywhere until he completes the first year of marriage. Feng and Bolin quickly joined the general. Even more so when they heard that they would not last more than fourteen days outside.
It was a nice sacrifice for another whole year of staying inside the walls. Cozy, warm, and safe. Where they did not have to think that someone was going to kill them in their sleep.