bqt:
I think XY loves XL however she is not sure if XL loves her wholeheartedly since he has his duties to the army and he hides his love from her, never declaring his true feelings. She, does not quite understanding her strong attraction to him, coupled with no confirmation on his side, does not feel certainty between them.
Jing openly declared his love for her, does things for her not expecting anything in return, and he submits to her biding. There is no doubt he loves her but he is a safe choice for her.
I think it's a question of.. would you choose the one that loves you (safe) or the one you love (uncertain)?
I feel her heart truly loves XL but because of childhood trauma and insecurities she choose Jing. Her love for Jing is a safe love.
Hidden love vs. open love is a part of it... but IMO it's a lot more complicated than that.
XY wanted someone who was committed to her and who would put her first. Someone who could abandon everything else for her. Someone who would live a peaceful life and raise a family with her.
XY has known that XL is on the opposite side of a war from her since the beginning. She knew he was not someone she could have a peaceful happy ending with. She comes to find out that, in addition to being her family's enemy, his loyalty to Gong Gong and the remnant army is unshakeable. He will not abandon them for her. He wouldn't give them up to go and wander the world with XY.
So XY tries not to let herself fall for XL, and later XL tries to push her away too (for her sake). XL was never a real option for XY. And when it seemed like she was leaning towards pursuing something with him anyway (e.g., by sending him the ice crystal ball) he didn't let her choose him. And throughout their whole relationship he hid his feelings from her. XY was probably aware, on some level, that they both had unspoken feelings for each other. But she could also see XL's behaviour. He wasn't offering himself as a romantic option. He was hiding his feelings (e.g., XY was aware that XL didn't want her to know about the things he did and said during her 37 years of healing) and put boundaries between them.
So, IMO, it wasn't just a matter of being unsure of XL's feelings. She knew that the remnant army was his priority. She knew that he could not abandon them, even for her. She knew he was not someone who could have a peaceful happy ending with her. And he didn't let her choose him.
I won't get into the reasons why XY chose TSJ in this thread, but I also think it goes well beyond him just being open about his feelings and devoted and therefore a "safe" bet.