Hi there, it sounds like a variation on a very common problem on the site! Cheeks has been used to being an only cat with your undivided attention and then along comes this young upstart who smells different and has invaded his territory. Some existing cats react with aggression but Cheeks sounds more confused than aggressive.
One good suggestion a member posted was to try and get them familiar with each of their scent. If you rub Cheeks with a towel and then the kitten you are transferring his scent to her - then if you do it the opposite way you transfer some of her scent to him. Smell is very important and if Cheeks gets used to that he should come round in time, even if they are never bosom buddies they will be able to share the house quite happily!
If anyone else has other suggestions, then come and reply
Good luck, let us know how things go