When you are gifted money or even stocks by family or friends (not an employer), then the rule is under about $14k per year you don't have to pay tax or report it. Over $14k you do have to pay tax. You can also have married couples split this up, so your dad could give you $14k and mom give you $14k for $28k total per year with no tax implications.

But, if your mom gives you $20k as a gift on xmas, you have you pay tax on that....or the IRS will come calling. This is not about being moral or immoral...it's about an existing US tax law and do you want to break it or follow it.

https://en.wikipedia.org/wiki/Gift_tax_in_the_United_States