I cannot help but be reminded of the Dragon Age: Origins line Is there something in your tent that needs ... assassinating? It indicated fairly effectively that if you proceeded much further you were going to be snogging / shagging the randy elf in question (and he would soon indicate he didn't do relationships).
I've not had the Bioware experience, but I suspect strongly that it's not as bad as the Wing Commander III experience when it comes to romance. Some thoughts come to mind:
~ The ME series takes place in everyone has sex all the time [http://tvtropes.org/pmwiki/pmwiki.php/Main/TheFuture][/I]. I'd wonder if Bioware has included any pretense or justification for how relationships work in the Mass Effect diegesis. (e.g. a severe labor shortage would drive people to hook up young and celebrate every child).
~ To note other examples of people from the future, Captains James T. Kirk and Jack Harkness both are open to (and in fact would proposition) anything that moves regardless of species.[footnote]In the case of Kirk, this is according to Gene Roddenberry, and was exemplary of Federation human society. The writers of Star Trek were less comfortable with this, and tacked on the '60s and '90s morality into their writing (note the entire absence of open gay relationships), but Kirk's kissing of the girl-of-the-week in The Original Series was accepted shorthand for no-holds-barred sex.[/footnote] Harkness is expressly open to relations with other men, yet cleanly flies under the gaydar.
~ Regarding Liara, while she seems reserved Zhaan [http://masseffect.wikia.com/wiki/Liara_T%27Soni] qualifies, any alternative to hair). Still, SNIPERFOX ft. Harry P.Ness may have it down that anyone (including the Reaper spy[footnote]When the moment is right, Shepard, I shall take your life for Reaper glory... But... you left me cake in the mess...and now, now I'm afraid I love you. Aghast! I am torn between duty and desire![/footnote]) will fall in love with Shepard over an extra slice of cake in the mess. But who, I ask, doesn't love cake?
~In the real world, I think it is a good thing that guys get propositioned and learn how to politely reject. Indeed, the other half of the populace is quite familiar with the necessity of rejecting unwanted advances; knowing both sides makes one a better negotiator. And the fact that we have grown men freaking out like tittering tweens being asked to dance for the first time (sometimes to the point of violence) is embarrassing to our species and our society. That said, sometimes the one rejected can't help but feel hurt. This is called (in psychological parlance) a narcissistic injury, and is a healthy thing, helping one's internal expectations better match reality.
~In defense of Bioware, simulating human relationships, what are possibly the most complex social models seen in the animal kingdom, is a very difficult thing, and the folks of Bioware should get credit just for trying, let alone allowing you to choose partners, even choices not entirely accepted by the mainstream. Eventually, we'll be able to effectively model how relationships do work (or how we want them to work). But for now, even trying and working them into commercial games is a step forward.
238U.[footnote]In the event that Escapist requires me to view a commercial before getting a code, I will simply not post. Depending on the frequency, this may temper or cease my future participation in the Escapist community. Apologies in advance, if this policy prevents me from replying to you when it is proper to do so.[/footnote]