Introducing my cat to a kitten help !

So my cat binx is about 9 months old and my bf brought over his little cousins kitten who’s maybe about a month or two old I’m not sure the age but she’s still super small in size. I know your supposed to slowly introduce them to each other my cat binx is pretty skittish so his reaction was to just hide under my bed! So I let him out my room so he could wonder around comfortably but he wanted to come back in and just stared at the kitten playing as I was holding him just in case he tried anything. He watched and started hissing at the kitten but wouldn’t try to swat at him so I let him out again after a couple minutes. My bf took the kitten back to his house this morning and I’m hoping the scent of the kitten helps cause my cat was smelling all over the toys and things he slept in last night. I’m wanting help cause I’m hoping to take in the kitten eventually any tips ??