It is a valid concern, ethically. Trist was a 2 yr old cat. Still almost a kitten. While he's blowing through the stages of human development a few a day, he's still very emotionally dependant on Jensen, which also adds to the "taking advantage" feeling.

Jensen should get Trist a collar with his name and address on it.

But Trist is an indoor-cat?

Yeah, he probably should.