Anybody know which manhwa/novel this is?

A very vague memory suddenly came to me. I have a very specific scene in mind and I'm hoping someone might recognise and tell me which manhwa/novel it's from.

There's a character, a knight, I will call him K. I vaguely remember K being desperate for approval from a guardian, either a father or an uncle. K had sex the night before and is in bad shape, backpain etc. Next morning, during training, K is made to spar with another knight. They spar and the father/uncle happens to show up to watch. As K is desperate to please that father/uncle, K tries hard to win the spar with the other knight. However, due to backpain, K makes a mistake, letting the other knight gain an advantage and win. K is devastated and I'm not completely sure but the father/uncle expresses disappointment to K. K had a friend and that friend vouched for K.

I'm not sure if it's the same manhwa/novel but I also have another scene. A knight, I will call A. A is a great knight, who everyone expect to become Captain Knight or something. A also helps train this other knight, I will call B. So same time every day/week, A trains B. A and B bonds. B eventually surpasses A and I think B becomes Captain Knight? I can't remember if A is jealous of B but they grow apart. B is in love with A. That's all I remember.

Much appreciation to anyone who can help me find manhwa/novel again. Thanks xxx