Honestly, that’s one of the topics I’m still kind of on the fence about. On one hand, he’s extremely indifferent, but on the other– if the dude is nearly 600 years old, how wouldn’t that be something he’s at least tried once or twice.
Love is very much not his thing and despite being aromantic (see: the whole kind-of-sociopathy-but-alien thing) it isn’t.. impossible, per se, just highly, highly unlikely. He doesn’t feel love as much as he would some kind of genuine, special affection (think: what one would feel for their BFF, basically; not romantic love and in his case not platonic either but very close, at least), which he might have felt a few times in his life.
Though with that being said, I feel like he’d view these things casually enough to be like yeah why not, though I also can’t see him as the type to really settle for someone (someone he doesn’t feel genuine love for which is, again, not impossible but borderline, really) even in spite of the headcanons I’ve seen floating around that say otherwise. He would play favorites and have people he prefers over others but otherwise is a pretty free spirit regarding these sorts of affairs (not to say he doesn’t have standards tho cause he DOES thank you very much) and doesn’t dip his toes into it that often.
So, tentatively yes? A few, perhaps, he’s taken that could call themselves his mates (yes, more than one at a time) that he remembers more fondly than the others he’s had briefly in his bed. This wouldn’t be something that would have happened often, really, and these mates have never been permanent– not because he got rid of them on purpose, really, but either because they a) died in battle or b) found greater success elsewhere (which he understands well because he also values work and personal success over things such as personal relations). Maybe five max in his years, most of them likely when he was younger, as I imagine the older he gets / the higher in rank he got, the more indifferent and jaded to these sorts of things he becomes / became (waste of time in his eyes).
However when all is said and done, when he has a legitimate romantic attraction to someone, he’d basically turn on his head in terms of how he acts with these sorts of things and get extremely possessive and monogamous (mine, mine, mine and no sharing).