In Mass Effect i tried to get as far as i could in dialogues with characters, even though i was trying to remain neutral as to not get involved with anyone so i could remain loyal to Tali in Mass Effect 2, despite my best efforts to remain neutral but view as much dialogue Ashley came up but i had to blow her off.

Now playing Mass Effect 2 and i'm beginning to worry that my interactions with Kelly may be setting on the path to romance her while when i get Jack i want to be friendly with her however my target is Tali.

I am wondering, in Mass Effect 2 is there a way to control the relationships without having to just flat out ignore characters (so i still get the chance to explore their dialogue). like a particular conversation response that'll lock me with them or something? i'm on the Paragon path.