I dislike the way he lie so much to her !
Really? I dislike her attitude towards him as if she's observing a bug under a microscope. I'm kinda glad he's kept secrets from her. It would feel so clichéd if he didn't. And the story would make no sense then either. Or didn't you read the flashbacks? Ktbn.
To shywifey: so you also understand why John had reason to feel betrayed by Arlo now? KT.
It's my turn to say Really??? I find your point of view very interesting. I do not think she observes him like a bug rather she admires him for always standing up for what he believes in and never backing down even though "he has no powers". He motivated her to stand up to her mother and to live her life how she sees fit. To her, he's the only person who truly accepts & respects her for who she is and not the power she has.

i can totally see sera feeling somehow betrayed & lied to. Things might possibly not be pretty for a while when she finds out, hopefully she's sensible and listens to reason when he explains.