Headphone splitter - for a phone / tablet, can anything burn?

Question

Headphones

I ordered a headphone splitter from Aliexpress so that I could plug two headphones into one jack. He is not strong in electrics from the word 0.
Father is strong, on this occasion, he says that you need to have a board in the middle (such as an amplifier), he says that due to the fact that there is nothing in the middle, you can burn in the pipe what is tied to sound.
I look at the reviews, there on Aliexpress they sell splitters for 6 headphones, and there are under 1000 comments, under such goods, and everyone is happy (if not satisfied, then the quality, and not the fact that they have something on fire).
Questions:
1) Is the father right?
2) If I stick a pair of 3.5 headphones (from an iPhone for example) into a pipe (Android, which is probably not the point), can something burn?
(I’m not at all competent in the topic, I need help, preferably from a real person who understands, and if the Father is wrong, then I could send him a detailed answer, what he is wrong about, and I myself can be sure that I won’t burn anything. Well, if I'm wrong, then OK, thanks anyway = huge for the help)

Answer 1

1. Without an amplifier, when branching, the current strength (and together with the volume) will drop by half.
   
2. If there is no separate resistor on the board with the amplifier that consumes the "extra" current, then with a single connection it will take on all the output power. Since the output power of portable devices is small (iPods, for example, gave out up to 60mW, i.e. a maximum of ~ 30 mA), it is unlikely that something will be burned, but there is a chance. Now, if you plug the headphones into a hundred-watt amplifier (again, without additional load), the headphones will burn out before your eyes.