It isn't fitting for a man of Ivan's station to serve a half-wild god.
Sometimes, his dates will ask him about it, their curiosity fueled by wine, or by lust or disdain. Ivan just grins at them, and says he needs a god who mostly stays off-planet and leaves him alone. Some of them laugh back at his easy, sexy blasphemy. Some of them leave.
A few times, his superiors alluded to it and Ivan shrugged, and he smiled when more pious men were promoted above him.
His mother thinks it's laziness, because serving Miles looks easy - and it is, really, and she can never know about the times it isn't. Ivan knows she loves the Vorkosigans more than she ever loved anyone else, but she's worried about Ivan's immortal soul and his mortal marriage prospects. She keeps her salon stocked with tasteful pamphlets about converting as an adult.
Miles thinks this is hilarious.
"You should invite Aunt Alys to the annual worship," he said one night, when they were both drunk and sprawled in Ivan's living room. "She'd curse us both out if she saw you standing alone with the delegate from Silvy Vale."
"You could get more followers," Ivan told him. "The Vor mostly hate you, but you could use that to get the proles to flock to you. You're just not making an effort." He trailed off, annoyed with himself. Sometimes, when he was very drunk, he sounded just like his mother.
Miles considered it, studied the ceiling.
"The problem with followers," he said finally, "is that they expect you to know where they should be going. That's easy enough with my district's hill-folk - any direction pointing away from infanticide is progress. But how would I know what some capital clerk, or archivist, or a gardener, would need from me? I can barely follow myself."
This made a lot of sense, so Miles was clearly lying through his teeth. Ivan said nothing, letting him have his delusion of humility, for the time being.
"And anyway." Miles stretched and placed his narrow, scarred feet in Ivan's lap. "More worshipers for me means a lot more work for you. My most esteemed acolyte."
"My trusted paper-shuffler. My most cardinal man."
Ivan groaned and Miles nudged him, not very gently. It was the end of the conversation.
Miles never asked why Ivan followed him. Ivan supposes the answer is obvious to both of them: because somebody has to.
If Miles had ascended earlier in life, Bothari would have given him all the devotion and all the work a god could ever ask for. But Bothari died a heretic and Elena fled into atheism, and when Miles finally changed his bones into immortal ones, only Ivan was there to light the candles on the dusty altar in Vorkosigan Surleau. He spoke the words of devotion, and snickered only once, at the part about divine serenity.
Now, each time Miles disappears, every time the rumors or reports say he was scattered to ashes on some foreign planet, Ivan is the one who sits by the altar and watches the candles burn down; he has a prayer that starts with 'you little bastard' and ends with 'come the fuck home'.