Why is my cat suddenly peeing everywhere?

my cat is nine years old, ive had him since he was 3 months. he was fixed asap. never had a problem, but recently he started peeing everywhere, specially on my parents futon. i have no idea why. his litterbox is clean, he is an indoor cat, drinks plenty of water, but has been craving it a lot more lately (possible sign of a medical problem). we will be taking him to the vet, but my parents want to kick him out and make him an outside cat after him being an indoor cat for nine years...help?? the three things i could think of is diabetes (my mom said she'd put him down if he did) a uti, or i do have a new boyfriend he may be jelous of, just a thought.