In my experience, NTs, and Ts in general love to be showered with physical affection from someone they like or love.
YES YES YES! /Meg Ryan mode off
I like to be touched, nuzzled, tickled, pinch, slapped, whatever.
And this is also how I show my affection. I don't have many "I love you's" thrown out there, unless she instigates and the correct social custom is to respond in kind. I also shower with subtle material tokens of affection. Before I get to this point, it depends on how comfortable I feel with the other person. Physical affection is easy once I feel like being close to you, and where I may differ from other INTPs or NTs, I don't have any problem lying about my personal feelings if I think it will help. I'd rather say "I love you" and not mean it than have you say it, have it go unreturned, and then feel terrible, because to be quite honest I don't have the tools to console you in this event. It's easier just to lie.
I also have no problem with PDA, whereas my SJ does. I'm very used to pretending I'm the only person around me and ignoring other people, so public displays don't really bother me. And, romantic relationships get the physicality bonus and side of me. Regular friendships do not, aside from relative displays of bromance.