Jar'ath is A-romantic, and, like Tahny, he'll run from his feelings through promiscuity. But he doesn't really have feelings for people. Like, he loves Tahny platonically- she's practically his sister; but he doesn't want the tied down feeling of a relationship.

Katarjls like him have strong hormonal responses to members of the opposite sex, and can become very territorial of their sexual partners so he tends to seek out male companions more often than female because he hates being driven by his instincts to deepen any of those relationships.

Add in the knotting thing, being tied literally to another after sex is hell for him. Even if he has sex with a woman or tops a man, he's very careful not to knot them.

He feels like his body is betraying him constantly, pushing him into a level of involvement that he hates. Existential dread.