Why is Mera trying to kill Aquaman ?

Hey I was looking at the new previews of comics and I saw a cover of the upcoming Aquaman and both him and Mera are trying to kill each other. So I'm asking why ? I thought they are happily married ? I only read Aquaman issues 1 through 24 so I'm very lost ?

@otaconmgs: That's not Mera. It's Siren impersonating her.

Ah, well that's a little different.

And here I was about to be all like:

"Mera trying to Kill Arthur? There you go with that BS again, DC."

She finally realized just how lame he was after all these years...

@lone_wolf_and_cub: Would you stop. You go into Aquaman threads just to say stupid things like this. You must have repressed liveo for him.

@blackwind: You do know Aquaman isn't real right? Lmfao, you defend him like he's your girl.

@xwraith: oh I see... So we're is the real Mera ?