Two Bone Whistles

I am the prince of the Yan Kingdom, and he is the proton of the Qin Kingdom. We were beaten together, and we secretly ate mutton soup cakes together. Each of us had a bone whistle as a signal. When we blew it, we knew the other party was coming. It was bone-chillingly cold in Handan in those years, but I feel like life wasn't that hard after all. Later I returned to the State of Yan, and he returned to the State of Qin. And then... In this life, are we considered friends or enemies?