Gambling would threat for you if you became so addict on it, if you are spending the whole time of you time with this, if you don't have things to do aside of gambling, if it disturb you from doing more productive things. Gambling could be considered as fun only if you can control it, if you can still do some productive things than betting.
Do not make gambling as your everyday doings, make it only as your way of entertainment.
So if you want gabling yo be threat on you, make it only as your entertainment or way to kill the feeling of being bored, I know people are being addict on it because of the reward that they get when gambling. Some considered gambling as source of income but actually that is not really possible because the chances of losing gambling is higher than winning.