Don't do it, man. Adding that coconut milk would seriously ass up the marinara sauce.

OR: The project was moving along smoothly until Jared completely assed everything up.

I've been jabbed

Ok baby, it’s time to ass up.

She was ass up and ready to go when I walked in the door.

Let me run to the bathroom first so I can ass up. I’m a little dirty down there.

bob:didn't you say you'd pay me back today???
ann:no, i sed tomorrow
bob:liz, didnt ann say she'd pay me back today
liz:umm...yea...she said that to me too
bob:i'ma need your broke ass to pay me back...now ass up.

*note-ass up can also be said as ass the hell up to add more emphasis to the fry or burn that just took place or it can be said as ass the fuck up to add EVEN MORE emphasis and make sed fry or burn even more epic...
just have fun with it

I don't wanna go there, that restaurant caters to the ass-up crowd. The movie we saw was totally ass-up. My coworkers were being so ass-up that I just clapped on my headphones and cranked the music.

Her booty is looking fly in them ass ups.

I tripped over a cable and fell flat on my face. Totally went Ass Up.