I don't like surprises. Too many bad memories.
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Frankly I don't care whether I know A, B, C and D are romanceable or not.
As a straight guy, my pool of characters is limited to the opposite gender. And, from the available female pool in ME:A, I can figure out the possibilities.
For example:
As a Male Ryder, my options are human female, Asari and the new female alien from the Helius cluster. A similar limited pool is available for other types. So, the "I don't want to know" crowd are sticking their heads in the sand. The choices are obvious. But, if the total pool contains multiples, say two Asari and three human females and two alien females, then the "who" becomes a chase of discovery.
Basically, once you know the character pool, chances are you can figure out the possibilities. The real question is whether the Bio writers decided to string you along with certain characters. Then, you to find out too late in the game, that you chose wrong.