Just to clarify, I am not asking about mature content as such, but the possibility to pursue romance, and to have your characters gender recognized and reacted upon, in both positive and negative manners.
In Daggerfall/Morrowind/Oblivion it was, aestethics aside, utterly pointless what gender you played, and that has always made immersion troublesome for me, in afore mentioned games. Fallout 3, and especially Fallout: New Vegas went a way to remedy this, although I missed romantic options, and found far to few situations were the LK/BW perks were useful.
This is a delicate balance to strike, I am aware, and once again, mature content as such is not needed at all. However, I did find it strange that sand-box RPGs with so much explicit violence,went out of their way to avoid mentioning any form of sixuality/desire/love/jealousy etc.
P.S.
I certainly hope this question is not against any forum rules; I've tried my hardest to phrase the question in an non-offensive manner.