So you swore a oath to a realm, but have no intention of staying and fulfilling that oath? And you call your character a noble?
Well seeing as you no longer need to actually swear an oath to change realms like you used to, No, I didn't swear an oath to the realm. Swearing an oath would be like me picking up an estate, which I'm not doing.
The better question is everyone else seems to accept this as reasonable as they are well aware of it.
I can only then conclude that this action is reasonable. If we're talking about honor though of nobility, just ask Tybalt about that. At least Malus somewhat did what he said he was going to.
