Hell, there's no reason that Javik has to be male at all, depending on their culture, or even a sex we recognized. Outside of being imperialistic, almost nothing is known about them. They could have had a hive/insect like society were the majority were undeveloped females. I get the feeling Javik wouldn't romance anyone, due to his ego. I personally saw that as part of his personality. Plus, well, no real time. While I love Samantha and Steve, their romances didn't feel finished to me. Which makes me sad. I could see Javik being possibly being romanceable after a few years of acquaintance, the time frame of the third game would have made it feel rushed.

As for Javik's birth/creation? That would make some sense. I doubt they would have had much time for natural conception when the Reapers arrived, not to mention that they would have wanted the best soldiers available. Hell, I could buy an origin similar to Grunt in a lot of ways, but we just don't know. Or they might have had a specific caste set aside to carry offspring, or lay eggs (though Javik does, I think, mention his birth. I'm going to assume that they meant live-birth, as opposed to an egg) that they were implanted with. It would free up the soldiers, again, so that the population could be somewhat replaced. There's a plethora of possibilities. ^_^ A lot of different animals have individuals that are sexed to roles that aren't male/female or jump back and forth, including some fish. Which, I kinda like that idea for the Protheans. Javik could be 'undecided' or something like that. Or perhaps, not sexually mature, having a life cycle similar to the asari? He's in something similar to the Maiden stage, where he's just not interested in sex yet? Huh. What to do here...