Upvote:1
Why would you need to fly back to HK late January, instead of staying with your GF? Do you have a job there? A family waiting for you? Study in University?
This is one of the questions you might need to answer to show that you have ties to Hong Kong, which would support your return there. You have obvious ties to UK (since you have a girlfriend there), so you'd have to convince IO that you would indeed return. They might also have a question about your relationship ("so you'd leave, and that's it?") as they might be concerned you're coming back to marry her. But the main concern here seem to be the possibility that you're trying to settle/find work/marry in UK.
This assumes you are also paying for all those trips yourself, and have means to prove it if asked; if someone else is paying for them, you'll have an additional concern to address.