Please don't try and learn grammar from songs. Use them for enjoyment and becoming familiar with native pronunciation but the only thing that matters to a songwriter/musician is that the song sounds good. Using 'don't' instead of 'doesn't' is common in songs. 'Don't' is one syllable, 'doesn't' is two so the former often fits the rhythm of the music better, despite it being grammatically incorrect. As for 'likes' having an apostrophe, that is just an inexplicable error. Also be aware that the lyrics you find online are often not from an official source. Often fans of the artist upload the lyrics themselves so they may contain mistakes such as this from time to time (especially if the person is not a native speaker of English.)

Please don't learn English from people like Justin Bieber, only 12 year old girls take him seriously.