If ESRB gave Mass Effect an M-17 rating due to partial nudity and thong underwear, UK's BBFC, on the other hand, has awarded BioWare's much-anticipated title a tame 12 rating. Which means that anyone aged 12 or above can play the game in UK.

The sex scene in question involves a series a choices that will decide who the player will...well, get to know each other with. Stated in BBFC's website:

The sex scene is triggered by the player making a series of choices about becoming more than friends with a colleague. If playing as a male character the scene can take place between him and a human woman or a humanoid female alien. If playing as a female character the scene can take place between her and a male human or a female humanoid alien.