Thes's Links
Thes aims to please, so at the beginning he'll try to impress them with his big words and (subjectively) attractive dragon body. He's got a high tolerance, but if they're nothing but rude to him he'll start to reciprocate that malintent.
Player driven; Thes is a much nicer antagonist, so they can be various degrees of kind or rude to him.
He'd say that there are earlier examples that count, but Deli is Thes's first "real" girlfriend. He never thought he'd get this far.
Deli initially intended to troll the heck out of "nice guy" Thes. Who knows how she was able to put up with him for so long, but good for the both of them that she did.
Thes is very envious of Bermudo's fitness. They're friends (and incompatible orientation-wise), but Bermudo's uncharacteristically encouraging attitude and Thes's general touchy-feeliness could lead others to misconstrue it as romance.
Bermudo has a lot of admiration for Thes's natural boons and potential. He's very encouraging around Thes in an attempt to raise his low self-esteem; he doesn't act like this around most. They're pretty good friends.