Nice work with some interesting possibilities. Thanks for sharing these.
Let's start by acknowledging that the purpose of the shot affects the evaluation. For instance, an ad for an escort service or a specific model/escort, I think #3 would be the winner, for an artistic shot I'd go with #2, and for a boudoir/steamy feel without being too explicit then it's #1. So it depends upon what standards you're using to judge the photo for each of these--and each of them is a very different photo.
Also, my position for shooting tandem work is that the models should show some kind of connection (even if they aren't touching). They shouldn't just look like two hot chicks next to each other. Maybe one looks angry or frustrated or whatever but you should feel from the photo that they're a couple or that they are interacting/connected in some fashion.
As to the photos themselves:
#1: Lots to like about that photo. I would prefer a softer light myself--this is a little too hard for my taste. If one model wants to hide her face, you could still reduce the dynamic range, bounce a little bit of soft light in there and hide her face while giving the photo a more romantic feel. I don't like how their hands in the lap are cut off by the thighs (removes some flow). And the hand on the shoulder--if you want a very sensual element that isn't explicit, she should be touching the strap to the bra or just starting to slide it off the shoulder. But it's a lovely shot that I'm sure both of the women like.
#2: my favorite. Yeah, a bit of noise. The biggest issue in my mind is that you've cut off the feet of the woman in the bed. But otherwise, this photo tells a story, it's got a nice composition. The right hand of the model in the foreground is too tense--she looks like she is nervous or angry...let those finger drape instead of clench. Or you could have that hand holding something (bra, champagne flute, a rose, a knife) that would add to the story in the photo. But it's a great concept and pretty good actually. "Bed" shots in which a figure is in the foreground can be very compelling.
#3: Could be a good portfolio shot for an escort who's face is seen. Here's what I'd change...the nose of the hidden face is sticking out the back/head of the seen model....if you could reshoot have her turn her head slightly to the right so her nose doesn't jut out and destroy the nice flow of the hair. I might have them open their legs just a big so their knees slide in between the other's thighs and they're a bit closer. This allows the hidden model/one on the right to slide her left hand around waist of the model on the left. This does two things--hides a little bit of tummy (which will occur with a pose like this) and you don't cut off the hand and remove a flowing line). Upper righthand corner is blownout (and that results in a loss of detail on the back of the right-side model). Also, if you're looking for an escort ad/portfolio shot than I'd make the model on the left a tad more playful in her pose (to match her expression). Take her right hand and she can undo the bra clasp of the model on the right. Or just caress the model's bicep. But make the pose fit the expression.
All 3 are nice work. You're right that tandem shoots can be challenging. You've got some good possibilities here that I think you can tweak a bit more. But I like all 3 of them.