There's no fixed answer to how it'll work when implemented.
Sometimes it's an unnecessary gimmick with little bearing on the story or connection to the gameplay, at others it can provide character development or be a natural conclusion to a relationship that's progressed through the game.
Games like Catherine and A Drug That Makes You Dream (Yume Miru Kusuri) utilized sex and sexuality quite well - and the latter quite explicitly - as part of their main storylines and characterization. Mass Effect seem to include it more as a side dish to the main story and gameplay, but since it's optional and doesn't seem to clash with the setting, I can't image it being problematic.
For non-prudes, including "Sex" in a game is really no different than including "Potato farming"; sometimes it'll fit in perfectly, sometimes it'll be a side quest some will enjoy and the rest can ignore, and sometimes it'll be a foreign element that doesn't fit with the story and setting of the rest of the game at all.
...
So should sex have a place in gaming? You bet.
Should it implemented in contexts/ways where it clash with the rest of the game? Of course not, nothing should.
Sometimes it's an unnecessary gimmick with little bearing on the story or connection to the gameplay, at others it can provide character development or be a natural conclusion to a relationship that's progressed through the game.
Games like Catherine and A Drug That Makes You Dream (Yume Miru Kusuri) utilized sex and sexuality quite well - and the latter quite explicitly - as part of their main storylines and characterization. Mass Effect seem to include it more as a side dish to the main story and gameplay, but since it's optional and doesn't seem to clash with the setting, I can't image it being problematic.
For non-prudes, including "Sex" in a game is really no different than including "Potato farming"; sometimes it'll fit in perfectly, sometimes it'll be a side quest some will enjoy and the rest can ignore, and sometimes it'll be a foreign element that doesn't fit with the story and setting of the rest of the game at all.
...
So should sex have a place in gaming? You bet.
Should it implemented in contexts/ways where it clash with the rest of the game? Of course not, nothing should.