No, we cannot betray God in Heaven. In Heaven, we will see God face to face and will be filled with all the love God has for each and every one of us.
All our desires, hopes, and dreams will be fulfilled in God and there will be nothing that can draw our gaze away from Him.
Just as a plant blossoms in the presence of the sun, “the seed of glory sown in man, will blossom when we see His face.”
It will be as impossible to betray God as it will be hide in a room full of light or to create a dark spot on the sun.
And the city has no need of sun or moon to shine upon it, for the glory of God is its light, and its lamp is the Lamb. – Revelation 21:23
In Heaven, God will be everywhere. His love cannot be overcome. He will wipe away all our tears, and there will be no more suffering.
Behold, the dwelling of God is with men. He will dwell with them, and they shall be his people, and God himself will be with them; he will wipe away every tear from their eyes, and death shall be no more, neither shall there be mourning nor crying nor pain any more, for the former things have passed away. – Revelation 21:3-4
The reason people betray God, the reason the devil betrayed God, the reason our first parents betrayed God, the reason we betray God, is because God gave us a chance to look away from Him, and we took it.
In Heaven, we will not be able to look away from Him.
Furthermore, we will not be able to sin because the prayers of our Dear Mother, Mary, will draw down God’s graces into our souls for all eternity.