The longer she touches him, the more he falls for her.
Trip doesn't know what this is, wouldn't admit it even if he did, but when T'Pol's fingers press into his face or back, it's like the deck below them melts away and they're suspended in space.
He has to admit that he'd continue to see T'Pol even if the neuropressure stopped working. He thinks he may have come to need her. Trip of three years ago is probably building a time machine just to laugh at Present Trip for that sentiment, but it's true.
And he's fine with that.