Gaming will my ps3 and ps4 be able use my psn at the same time?

[KefkasMyDad]

prolly been asked be4 but i just wanna be sure.
i want to give my bro my ps3 when i get my ps4 and i want him to have access to all my games on my psn account, i just want to be sure that me being online on my psn account on ps4 doesnt clash with him being online on my ps3. seeing as there isnt any issue with the vita, i doubt it, but i just wanna be sure.

 

[Clarky]

As far as I recall from e3 it shouldn't be a problem no

 

[GameWinner]

If Vita can why not PS4?