I'm back....it left me speechless.
Would you like a link to the video i just watched?
Maybe the "us" was referring to the Holy Spirit or sometimes called the Holy Ghost in the Trinity that explained throughout the Bible.
Also remember that the only sin Jesus said was unpardonable was to blaspheme against the Holy Spirit or Holy Ghost.
Example in Mark 3:20-30
Now what we can notice about that situation, is that the pharisees were not slandering Jesus, Himself, or even God, but rather they were slandering what was inside of Jesus, that allowed Jesus to cast out demons from people. So they were slandering against the Holy Spirit, and this obviously really upset Jesus and God to the point that Jesus said they would never be forgiven for it.
So here we see the entire Trinity together in action, Jesus being the Son of God yet also the Son of Man as Jesus was born of God but also born in a human body, and God is Jesus' father and speaks to Jesus, and Jesus carries out God's will, and then there is yet the third in the Trinity, the Holy Spirit/Ghost that dwells inside of Jesus, and clearly Jesus has immense respect for the Holy Ghost, much like how someone might have immense respect for a loving mother. I think most of us can recall from our societies how much of an insult it is when someone insults your mother, and how otherwise very peaceful men can become enraged when someone disrespects their mother.
So perhaps the "us" referred to in Genesis and elsewhere is both God and the Holy Ghost, as the Trinity had always been there, such that the coming of Jesus was prophesied long before His birth.