Four reasons why Ziam is real…

Exhibit A

OMG Zayn! Stop it. 

Exhibit B

Yes, Liam! Signal your boyfriend to the bedroom.

Exhibit C

Stop it, the both you! My heart can not take this!

Finally, Exhibit D

OH MY GOD! Just kiss already!

So from the evidence presented above I conclude that Ziam is real. 

(Gifs used not mine, credit to atoughlover.tumblr as original source of gifs)