Morning, ladies:
If you all remember, I promised to give a full, unbiased report on the Jacob Romance when I finally finished it. Poor Meghan Shepard, her price to end up with Garrus was putting up with this.
I try not to take parts of a romance separate from the whole. Considering only sections of dialogue ends up with out of context clues and inaccurate analysis.
I can now, without a doubt, say that Jacob's Romance, through no fault of the character, is terrible. FemShep is badly written and overacted during it. She just met the guy and is coming on to him like a drunken cheerleader at a high school prom. There is no reason to trust Jacob, at all, during the romance, but she's all over him and has to talk him into the relationship to begin with. I agree with FemShep being a sexually confident woman, but that was ridiculous.
Also, during "the birds and the bees" talk with Mordin, he cautions her about Cerberus bugging her body! I can never completely shake the idea that TIM put Jacob and Miranda on board the Normandy as some sort of sexual spy. Both eventually jump ship to your side, but even then, how could your really trust them?
I haven't romanced Thane yet, but in comparison to Garrus' romance and Kaidan's in ME1, Jacob's felt forced and overly sexual, as if there was no real feeling on Shep's end at all, that it's just a romp in the hay. He's the only LI to completely take off half his clothing, and is definitely overly developed. FemShep pounces on him, literally.
However, in ME1, the romance was gradual and the "payoff" wasn't forced. From the very first conversation with Jacob it seems to be about sex. There was at least a period of getting to know Kaidan before Ilos and sex was never really a topic of conversation. Unless you were teasing him about adolescent relationships on Jump Zero.
Garrus' romance, in stark contrast, built even slower. She were his mentor and friend in ME1. ME2, he tried to live up to her example -- for whatever reason you want to give him for doing that, unrequited love, frustrated over the abuse of Shep's memory, all of the above -- and it makes more sense for FemShep to be obvious in a sexual discussion with her pal than a stranger in a clandestine organization she can't trust.
The only way I can conceive of the Jacob romance making any kind of sense is if you're playing a Renegade or Renegon Cerberus sympathizer. Or your Shep just wants to get laid.