Changing the litter box. ..

How bad is it really? If i just do it a few times. Im out of town 4 days a week working and my SO doesn't do the litter box. His kitten needs to be nuetured and we've well I've made the appointment. I seriously just lost it when i saw the cat peeing in MY STORAGE BOX. i seriously cannot stand when animals pee on things. I don't know if it's because the litter box is filthy or because my SO took too long to schedule his neuter appointment.

I'm so annoyed. He just agreed to clean the boxes ONCE a week.... NO. I used to clean them way more than that. I work so much. I wish things could get done without me.