The first picture on this page is amazing. Really talented artist. That might just be my favorite Thane fanart.
I don't consider it as cheating if Shepard moves on with someone else after the way Ashley/Kaidan acts on Horizon. They practically ended the relationship right there, and a letter isn't always good enough to fix that. Too little, too late. It's more of a tricky situation with Liara. Shepard doesn't have an opportunity to end the relationship until LotSB. Now I have a question for those of you who have DLC. If you play LotSB early, before you start a romance with someone else, can you still break up with Liara, or does the subject not come up at all, basically forcing you to "cheat"?
As for romance traps, everyone's game seems to be different. I got the Liara trap. I managed to avoid the dialogue that others say leads to the Ashley trap just because of accurate romeplaying (the same thing that got me into the Liara trap, ironically). I didn't get the Kaidan trap, and I've played FemSheps who were friends with him and turned him down after the "Are you sending me signals?" dialogue. I thought that in addition to recruiting her last, the Liara trap could also be avoided by choosing the "Let's be friends" line (as opposed to the bugged "I'm not interested" line), but I recently discovered someone who's game has that line bugged too. So I think the lesson here is: tread carefully or just avoid anyone who likes your gender.
mythlover20 wrote...
Pfft. Oh that would be hilarious. I'd definitely go along with Mordin with that just to see Carson's reaction.
That dialogue really cheered me up. I've just been trying to recreate my MainShep Margurite so I can get her facecode and put it into the PC. That took over an hour and a half to do, and it is most definitely not right, but it's as close as I'm going to get her. (Why, oh why doesn't the facecode show when you import a ME2 save?!). Please remind me never to loose track of my facecodes again. That was truly an exercise in frustration. 
You can still join him!

I'm sure Carson will run through red sand again soon enough. Glad the dialogue cheered you up.
Ummm, I don't know. I don't think anyone here has done that. Well, maybe Saren. SAREN!!! Have you done this?
For the record, this is the first thing I saw when I entered the thread. xD It amused me.
To answer the question - yes, I think the official romance starter with Thane is the "I'm here for you" line (labelled as "I want you" for the purpose of being obvious, as the actual dialogue is not). The "friends" line, although it does sound flirty, probably isn't a romance starter - but it definitely works to play it like one for some Shepards.