Normal Behavior For Older Cat When New Kitten Comes?

I have a 7yr old cat and 1 yr old kitten. The kitten is doing better than the older cat. My older kitty has been urinating in the house, not outside like she normally does when someone comes over to visit or strange people come by from out of town. I don’t want to take them away from each other but it embarrasses me that they are acting this way! Both cats love each other and will go up on their hind legs together for attention…i think they may be fighting because he’s really jealous…perhaps if i put a baby gate between them? What can I do?