Introducing New Kitten to Resident Cat?

I'm in a bit of a pickle. About a year ago we bought two cats from one litter, so two brothers. The one shy and the other social and playful. After they settled in they changed behavior completely, like they swapped personalities. To cut a long story short the now new reformed socialite was out every night and sadly was run over a few weeks ago.

Now it seems like his brother, 'our ornament' cat has taken over the duties of chasing tail every night. He would be out all night almost and late coming in to eat and sleep. So we thought he's alone and we'll get him a friend since he seemed lonely.

Earlier tonight we adopted a kitten who was ridiculously scared and jumpy. We were told once 'she' is given the right love and attention she calms down and will be around you all the time. After we got home our male cat came in to eat as usual. At first he didn't notice the kitten and when he did, the kitten hissed and growled at the adult male cat.

This to us seemed weird since we were expecting a different reaction.
However, I started playing with the kitten while the adult cat left to avoid the kitten. As I played with him I noticed that it was in fact not a female but a male kitten. Shortly before I started typing this the adult male cat came back and I attempted to reintroduce them, but the same happened amd the adult male left again clearly upset.

Here are my questions. Will the new kitten relax and accept that he's not the only cat or would I need to give the kitten back and get a female? I don't want to make our male adult cat unwelcome in his own home. I also don't really want to send the kitten back to the dreadful past he had where he was scared shitless. What can I do? Could someone please help with advice that'll work? Much much appreciated in advance.
Kind regards.