Romance

Romance is possible in Mass Effect and Mass Effect 2 for both male and female characters.

Mass Effect
In Mass Effect, Commander Shepard has the option to pursue heterosexual romantic involvement with a human squad member - Ashley Williams for males and Kaidan Alenko for females - or xenophilic romance for both genders with the asari squad member, Liara T'Soni. Regardless of gender, Shepard can also have a sexual encounter with the asari Consort, Sha'ira. At some point in the game's development, it was also possible for females to romance Ashley Williams and males to romance Kaidan Alenko. This was later removed, although the voiced conversations for them remain in the game.
 * Attraction - When waking after Eden Prime, Shepard will find either Ashley Williams or Kaidan Alenko waiting at the Commander's bedside in the medical room, feeling guilty over getting snagged by the Prothean Beacon. Shepard can be reassuring and claim there was no way to know what the beacon would do, at which point Williams or Alenko will look much happier and a little intrigued.


 * Courting - After completing the first primary mission on each key world - either Therum, Noveria or Feros - Shepard can speak to either Ashley or Kaidan and begin building up a rapport that gradually grows into a romantic interest.


 * "Dr T'Soni?" - Once Liara T'Soni is on board, Shepard can also court her as above after Liara admits looking into Shepard's background. Although temporarily stopped, this rapport can continue after Shepard's second encounter with a beacon through another set of dialog options with Liara. If Shepard has spoken to Liara at all, even platonically, and is already involved with either Kaidan or Ashley, during the next conversation he or she will ask if Shepard is attracted to Liara. Shepard can either express an interest in Liara - which will effectively end the romance path with that squad member - or explain their relationship is only professional.


 * Two's Company, Three's a Crowd (optional) - If Shepard has been wooing Liara and the human love interest at the same time, after the next completed mission on a primary world, the commander will suddenly be confronted by both potential love interests after the debriefing. They will ask Shepard to choose between them. Choosing one will continue that romance and end the other (and no, Shepard can't have both: if the Commander suggests it, the human love interest will leave and the romance will be continued with Liara).


 * Sacrifice - On Virmire, Captain Kirrahe will ask for one of the squad members to join his diversion effort while Shepard infiltrates the base. Both Ashley Williams and Kaidan Alenko will volunteer, and Shepard is forced to choose one of the two potential love interests to risk in the assault. Later, near the end of the mission when Saren attacks, Shepard will be forced to choose which squad member dies in the nuclear blast. Sacrificing Shepard's current love interest will end that romance path.


 * Lockdown - While there's really no time to woo the commander's romantic interest during the pursuit of Saren, they will come to Shepard's side after the argument in the Council Chambers. Only a decisively Renegade conversation path will negatively impact the romance at this point; otherwise the romantic interest will comfort and reassure Shepard. However, the intimate mood is immediately shattered by Joker with an urgent call over the ship's comm.


 * Conclusion - If the romance subplot has been continued, while en route to Ilos the love interest pays a private visit to Shepard's personal quarters aboard the Normandy. Paragon choices will make for a passionate ending and an intimate cut-scene.

Completing the romance subplot unlocks the Paramour special achievement.

Asari Consort
After completion of the assignments associated with the asari Consort, Citadel: Asari Consort dealing with Septimus and Xeltan, and upon returning to the Consort's Chambers, Sha'ira will offer a reward of words, "an affirmation of who you are and who you will become." If the Commander expresses dissatisfaction with the offered reward, Sha'ira will initiate a sexual encounter with Shepard.

Mass Effect 2
In Mass Effect 2 Commander Shepard encounters several potential love interests.

For a male Shepard they are:
 * Tali'Zorah nar Rayya, the Quarian technician
 * Miranda Lawson, a Cerberus operative
 * Jack, a powerful biotic prisoner and test subject
 * Kelly Chambers, the SSV Normandy SR-2's Yeoman, psychologist, and Shepard's personal assistant

For a female Shepard, they are:
 * Garrus Vakarian, a turian vigilante and former C-Sec officer
 * Jacob Taylor, a Cerberus operative
 * Thane Krios, a drell assassin;
 * Kelly Chambers, the SSV Normandy SR-2's Yeoman, psychologist, and Shepard's personal assistant

It should be noted that after the suicide mission, Morinth and Samara are also possible romance options for a male or female Shepard. If you choose to romance Morinth it will cause Shepard to die, whereas romancing Samara reveals that she also has feelings for you, but as her duties come before romance, it can never be.

If an imported Shepard has a love interest from the original Mass Effect, then that relationship will continue into Mass Effect 2, even though the love interest will be unable to join Shepard's squad. However, it is possible for Shepard to be unfaithful and pursue a relationship with one of Mass Effect 2's potential love interests. Acting unfaithfully is expected to have negative consequences for the relationship in Mass Effect 3, provided this Shepard survives the events of Mass Effect 2. Additionally, in Shepard's Cabin, a picture of his or her love interest from the original Mass Effect is visible. If Shepard pursues a new love interest, the picture is turned face down on the desk. There are no actual romance plots with the original ME1 love interests, but should Shepard stay loyal to his or her original Love interest, they briefly exchange a kiss when reunited and a small cutscene enroute to the final mission takes place in which Shepard stands over and stares deeply at the photo, smiling.

After you have beaten the game and chose a new love interest, you may invite him or her up to the Captains Cabin to either sit with them on the couch, or rest with them on the bed. If you are in a romantic relationship with Kelly, when you invite her up, she will in addition dance for you. Kelly will also feed your fish.

Mechanics
Romances are built through conversing repeatedly and answering favorably when the subject is raised. Both male and female Shepards will have identical dialogue when first meeting their crew members. New dialogue options only become available when missions or assignments are completed. However, once a crew member's loyalty mission is available, there are no more new dialogue options available until it has been completed.

Eventually, gender-specific dialogue options will give the opportunity to express interest in a squad member, eventually ending in a sort of romance-zenith where no new dialogues are available despite completing missions. At this point you know you have successfully 'locked in' that romance, and proceeding through the Omega 4 Relay at this point will trigger the romance scene (Jack is an exception, as it is possible to have sex with Jack before going through Omega 4 Relay). All romances end in a love scene immediately after entering the Omega 4 relay. While you can attempt to romance more than one crewmate, only one romance scene will ever play here. After completing the suicide mission, you are given the choice to pursue relationships with other team members provided that Shepard and the squad survived.

Once a subject has been 'locked in', you can still express interest in other crew members. However, at one point they will 'challenge' your love-triangle and force you to dump your 'locked in' option. Once a potential relation is at the 'challenge' part, there is no way to express disinterest in them no matter what you choose. However, if you dump someone who is 'locked in', that romance option isn't ever available.

Media Controversy
The inclusion of a sex scene in Mass Effect led to some controversy and inaccurate rumours made by Fox News after its content was misunderstood. These rumours have since been quelled. An additional message that can be found in Asteroid X57's pirate radio shack (in the PC version of Bring Down the Sky) may be a "response" to this controversy.