Why was jasaina into skel?
Say what you want about her, but Jasenia was a real one. She obviously didn't choose Skel for his looks, his money, or his size--both height and otherwise...She loved Skel for Skel!
Basically they have known eachother all their lives. The Barhatian royal family bought Skel from slavers when he was a baby, as a gift to Jasenia's eldest sister. Baby slaves are a common gift for children in Barha unfortunately...The idea is that it gives girls child-rearing experience, and at the same time, there is no risk if she hurts them because they're "only a slave". A slave's life is worth next to nothing in Barha's jurisdiction. They're treated as disposable objects by royalty because money is clearly not an issue for them.
Jasenia grew up with Skel, he was the first friend she ever made aside from her siblings. She was just a toddler, she had no concept of slavery and didn't realize he was different from her in any way. All she knew was that they were friends and she liked playing with him.
Her sister grew out of playing with baby dolls (and by extension, baby slaves...) so Jasenia "inherited" Skel as a hand-me-down toy. This bought him more time before her parents forced him into actual slave-duty. For the time being, his job was to just play with their daughter and keep her happy.
Skel didn't even realize he was a slave until later in life, he thought he was royalty too! He got to eat at the table with the royal family, play with the princess's toys, wear nice clothes, and never had to work. The other slaves were wearing rags, eating gruel, and sleeping together in cramped bunks in the basement. Sure he was a goblin like them, but how could he believe he was on their level when his life was so different?
When Jasenia reached puberty, her parents tried to make Skel do slave-duty, but she screamed and cried and threw such a fit that they decided to just leave him alone and let him continue being her playmate. Jasenia has never thought of Skel as a slave, he has always been her friend first and foremost, so she never let her parents treat him like anything less than family. She even convinced them to let him learn magic from the palace wizard, which is absolutely unheard of for Barhatian slaves.
By this point, Jasenia and Skel were getting romantically involved with eachother and had already decided they would marry when they were older. (Of course the King and Queen gave them a rude awakening about this later, but...)
As the princess of Barha, Jasenia was quite sheltered and wasn't allowed to hang out in town without an entourage of security personnel. Why bother going out to party if you have to take your babysitters with you? Any friends she made were fake suck-ups who just wanted her money and a piece of her clout.
So naturally, she gravitated closer and closer to Skel over time because he was her only "real" friend.