Not sure if it's what the OP is getting at, but what I'm curious about is:
What conditions lead to Mako and Torian's romance arc? Does it happen regardless of the BH's gender? Is it based, as I've seen described, on Mako's and Torian's relative affection levels? And does it have any impact on your character's ability to romance one or the other of them? (This last, I think, is what OP is concerned about.)
Playing a fem BH, I'm planning to romance Torian, but Mako's affection will certainly be higher than his when I first get him as a companion. Should I be concerned? Should I sit Mako down for a talk, gift-spam Torian, let them have their chance, or what? (Wait, do I really want to be a rebound?
The problem is I've been told that if you're male and want Mako, you need higher affection with Torian to stop it from happening, and if you're female, higher with mako than Torian.
However, I'm into Act 2 and already got all the conversations done with her because I was sitting just under 9k affection with her prior to Act 2 and since I blew through all of them in one ship visit, I don't know if I locked myself out or not. However, as I stated, I don't have Torian yet, so whether that is a factor or not, I don't know.
TL;DR- Is it Act 2 or Act 3 where one of them will play homewrecker is what I'm asking? If it's Act 2, I'm probably hosed, but if it's Act 3, then I can just opt out of using Mako in conversations entirely until much later.
One final tidbit, is it just me, or does no other class have to deal with homewrecking companions?