do you have more than one cat.

We have 5 cats. They were outdoor cats up until two months ago when we moved them down here to TN from Illinois. We have been keeping them inside and only started letting them go out last week. They only stay out for 15-20 minutes and then come back in. The outdoors here is new to them and scary. BTW, the bathtub pee-er has always done this whenever he was indoors. He is 6 yrs. old.

could you put a litter box in the tub? I did this with my cat to stop the dogs from getting to it and disturbing her when she was using the litter box. the great thing was, if she missed the box it was an easy clean up :)

over time you could probably then slowly move it out of the tub if it bothers you having it in there, but since she is using the tub anyway, I would put a box in there.

It could be because he doesn't feel safe while using the litter box (other cats & dogs?), the litter box is dirty or used by another cat, and sometimes it's a sign of a urinary problem. Has he been checked by a vet recently?
If you have more than one cat, add another litter box.

i think that's because he's so nervous

He is a very laid-back cat --- is friends with the others and with the two labs. I think he is just lazy sometimes and doesn't want to go down to the basement. He doesn't do it often.

you basically answered your own question. 5 outdoor cats moved inside. Instictively, they are all naturally going to mark territories for relieving themselves. Adding more litter boxes may help, but most likely not.

Your cat maybe pets in your bathtub because it finds its odour in there . You should better try removing the smell from there and making a litter box for your cat.

The goal is not to add more litter boxes --- they have those in the basement. The goal is to have them use the great outdoor bathroom. These are mostly outdoor cats that we brought with us when we moved from our farm in IL to acreage here in TN. They are little by little getting used to being outdoors here but it is a whole new situation for them so it will take time.