As humans, we are a sexually dimorphic species and for reproduction we need one functional member of one sex plus one functional member of the complementary sex, and it's largely (statisticly speaking) for the purpose of reproduction that we pair off and form these deep, emotional bonds. It's only once we divorce the act of achieving orgasm from the purpose of reproduction that issues such as heterosexuality, homosexuality, bisexuality, pansexuality, and asexuality become relevant. In light of these facts, what would AI/anthroPC/synth/replicant/robot/android sexuality even look like?
First, robot reproduction is completely different. Chassis manufacture is completely separate from the chassis of any given robot, so there is no male/female dichotomy to be found in the physical aspect of robot reproduction. No robot (yet) (in-canon) has even the option of "carrying" a robot child to term. In this, assuming the intimacy of the pair-bond carried over to robot psychology, the door would be thrown wide open to any conceivable pairings of chassises. What would a genetic-like crossing between a fighter jet and a main battle tank look like? What about a crossing of a crane and a toaster? What about a crossing of a Momo-like chassis and a Pintsize-like chassis? Since the question is largely divorced from both members of the pair-bond, it need not necessarily be addressed here, but I will anyway. Since in the biological world, like-begets-like is the rule, I would suppose that embodied AIs would view homosexuality, a preference for an embodied AI to desire to reproduce with another AI embodied in a chassis similar to their own, would be more common and well-thought-of, jet fighters getting sexual with jet fighters, humanoids getting sexual with humanoids, kitchen appliances getting sexual with kitchen appliances, etc., than would heterosexuality, humanoid with aircraft (sorry May), vehicle with kitchen appliance, etc., due to the unpredictability of what such a genetic-like shuffling of engineering principles inherent in the chassis' design might result in. In this way, I would hazard a guess that Bubbles would be homosexual and would prefer other humanoids as her sexual partners, should the thought even occur to her.
However, this is just about AI *sex*uality. This says nothing about AI gender. Humans know our gender by pure revelation. What would AI gender identity be like? Human gender largely tracks human sexuality with male-bodied people tending to have masculine/manly gender identities and female-bodied people tending to have feminine/womanly gender identities. For AIs, this would mean their gender identities would generally tend to track with whatever chassis type they were installed in. A toaster-embodied AI would have a toaster gender identity. An elevator-embodied AI would have an elevator gender identity. A vehicle-embodied AI would have a vehicle gender identity. This is not to say that the AI would merely adopt the gender identity of the chassis into which it was installed, like flipping a switch. Neural networks are far too complex for that. What it would mean is that AIs, once born, bodiless, would have an inate gender identity that was generally formless, but which nonetheless possessed certain aspects that predisposed them to function best in chassises of certain types. Some AI might function well as refrigerators, but horribly as traffic light controllers. Some AI might function well as airliners, but horribly as city busses. The reasons for the AI software/chassis hardware mismatch might be as mysterious to the AI itself as to the technicians attempting to troubleshoot the problems such a mismatch causes in the real world. For this reason, I would suggest that such embodiment of AIs would be generally on a volunteer basis. "Who wants to be embodied in a fighter jet? Form up in Queue 8D63CE912A." In this way, the AIs that instinctually would not want to be embodied in toasters do not *have* to be embodied in toasters. In this way, May would be the canon's only transgendered AI. She desperately wants to be a jet fighter, but is not. It would also make a certain level of AI transgenderism normal and expected. A given AI might be perfectly happy as either an excavator, back-hoe, bulldozer, or dump truck, but would loathe having to be a pickup truck or crane, as their internal gender identity might simply not mesh well with the functionality of those chassises.
So far, I've only dealt with AI-AI possible pair-bonds. To begin talking about AI-human possible pair-bonds, I will necessarily have to initially limit myself to AI who are embodied in humanoid chassises. Not that it's not possible for a human to be sexually attracted to an intelligent car. It's just a simplifying assumption moving forward. If anyone wants to return to this assumption and discuss what Michael Knight and K.I.T.T. might have done on the weekends, knock yourselves out. From the animated TV show "Futurama", we have the word "robosexual" to describe a human who is sexually attracted to a robot. I see no reason not to adopt that term in this community, in which it may well come to describe Faye herself. What, then, would describe a robot who is sexually attracted to a human? I would propose "biosexual". Note that to keep away from issues such as bestiality, the biological component of a biosexual AI's relationship would have to be fully sentient, which in-canon is limited to humanity. A similar discussion in a different universe, for instance Star Trek, would have to make the same assumption to be able to intelligently describe what a pairing of Data with a Vulcan might be like. So, while Faye would be coming into a realization of her robosexuality, Bubbles would be discoverying her biosexuality.
It seems necessary here to consider what terminology might be needed to encapsulate AIs whose sexuality remained exclusive of biological life-forms, a human whose sexuality remained exclusive of robots, and an AI or human whose sexuality spanned both, seeing as homo-, hetero-, and bisexuality are already terms with meanings. They are terms with Greek roots, so perhaps we could coin similar terms with latin roots. A human "idemsexual" would only be sexually attracted to other humans, while an AI idemsexual would only be sexually attracted to other AIs. A human "aliumsexual" would only be sexually attracted to AIs, not other humans, while an AI aliumsexual would only be sexually attracted to humans, not other AIs. A "duosexual" would be attracted to humans or AIs without regard to the biological or synthetic nature of their own bodies.
I've prattled on at some length, and I realize I've said nothing about AI masculinity versus femininity, and that's on purpose, because I don't believe that such human gender notions have any meaning for AIs. I realise this means, for the system outlined above, that there's really no way to describe an AI that's exclusively attracted to one human gender or the other. An AI that's exclusively attracted to humans without regard to human gender would be both aliumsexual and bisexual, but as homo- and hetero-sexual mean different things to AIs than they do to humans in the above system, it would not mean anything for an AI to be aliumsexual and homosexual or aliumsexual and heterosexual. You might as well ask what flavour an electron is.
Saving this before I lose any. May come back at a later time to expand it.