If USA INS officers check your and your relative's documents seriously, they will deny your entrance into USA because you don't have USA visa. The worst case is that INS officer will think your relative is smuggling people into USA. If such things happen,
your relative will be in trouble.
Of course, INS officer does not all passengers carefully, so you may sneak into USA. However, you are taking great risks.
What I told you is based on the true story.
I strongly advise you not take risks.
You will have a lot of opportunities to come to USA. Don't hurry.