Just in case someone randomly finds their way here and wants to have BroShep romance Kaidan or FemShep romance Ashley, there is an option if you're playing on PC! Yes, gender swap is possible using the console, but it sucks. Nothing worse than BroShep getting called "Princess" by Harkin in Chora's Den because the NPC's don't notice the change (though Ashley and Kaidan will become romanceable). However, in the last year or so, a mod has come into being that fixes all that! It can be found on NexusMods here: https://www.nexusmods.com/masseffect/mods/80.