Truth is, the first time Shepard gets Garrus's clothes off, she's not quite sure how to react.
Half of her feels something protective--he looks frail, almost, that trim waist, the long, lean arms. And beautiful--the light catching on his plates, in his inhuman curves, like some kind of sculpture. She's so used to him with his heavy armor on; seeing him with his shoulders reduced, his impressive collar diminished, gives her the urge to shield him, teeth bared, rifle ready, defensive. And the smooth, sexless plates that curve between his thighs, almost another guard, living armor…
But the other half wants to put her hands on him, see if he's warm, feel his bared body under hers. Sexually? She doesn't know. She's aware of him, shifting his weight nervously, one three-fingered hand coming to grip the opposite forearm. His eyes on her expectantly, the hitch in his rich, dual-toned voice as he says,
"See anything you like, Shepard?"
Awkward laughter, as he halfway spreads his arms, takes one uncertain step towards the bed.
Does he want her, she wonders. Or does he look at her, halfway-stripped down, and wonder what the hell they're getting into? She glances again at his strange, alien body, and then down at her own. At her grey, utilitarian underwear, covering her breasts and crotch, at his genital-less groin.
"Interspecies awkwardness thing" starts to look too damn likely for her tastes.
But then he's at the mattress, pressing one knee down beside her, sinking it so she tips against him. She feels him, startling, fever-warm against her skin, as he lowers his head towards hers. Sees the sharpness of his teeth behind his mouthplates and mandibles, and she knows they'll never kiss, and she wonders if they'll have something else.
He touches his forehead to hers, and she thinks they will.
She discovers he has a strange, raspy tongue, that makes her ticklish at first and then sigh with pleasure later. She discovers his fingers can fit inside her, hot and smooth, like some strange jointed, bumpy metal toy, and she teaches him how to hit that spot--that one--deep inside her. She discovers he likes the feel of her fingers under his fringe, and when she scrapes her teeth over his mandible he shudders and moans and clutches her. She discovers the smooth plates protect his strange, almost unfurling cock--never meant to fit inside her properly, too long, too stiff and too flexible all at once--but somehow they make it work. And she discovers that she can still giggle like a school girl--her, Commander Shepard!--as they clumsily fuck and he slips out for the third or fourth time and she was so fucking close but she can't help it, the look on his face is so priceless--so earnest--so fucking Garrus-- that she's not even sure if she cares if anyone on the Normandy ever finds out.
The thing is, they fit. If he can barely lie on her bed, with his strange curves and stiff carapace, she piles pillows for him, makes the bed fit him. If she aches after they sleep together, in the worst places, places she didn't know she could ache, he's there to rub the analgesic lotion into her, soothes her, massaging her until she drowses contentedly. If he's confused by her breasts, by her softness, by the way she wants to put her mouth in places he thinks mouths were never meant to be, he still moans and tears into the blankets and startles himself by coming under her soft, human attentions.
Maybe he doesn't have a human fetish. Maybe she'd never care to fuck another Turian. It doesn't matter. When she sees him now, beautiful and bare, eyes searching her face, she wants him like nobody else.