No, let's try mouth

You look at Liv, face against the ground with her gaping asshole in the air. She's still a zombie.

"Hm.. better try the mouth" you say, moving round to her head

"Wait, that was JUST in my ass, it just filled me ..." Liv starts before you thrust your cock into her mouth anyway

Now, you could let her suck it at her own pace or you face fuck her until you cum down her throat.