From the CCC:
2093 Faith in God’s love encompasses the call and the obligation to respond with sincere love to divine charity. The first commandment enjoins us to love God above everything and all creatures for him and because of him.12
2094 One can sin against God’s love in various ways:
- indifference neglects or refuses to reflect on divine charity; it fails to consider its prevenient goodness and denies its power.
-** ingratitude** fails or refuses to acknowledge divine charity and to return him love for love.
- lukewarmness is hesitation or negligence in responding to divine love; it can imply refusal to give oneself over to the prompting of charity.
- acedia or spiritual sloth goes so far as to refuse the joy that comes from God and to be repelled by divine goodness.
- hatred of God comes from pride. It is contrary to love of God, whose goodness it denies, and whom it presumes to curse as the one who forbids sins and inflicts punishments.*
I think your example would fall under the bolded line.
I’m not sure if the following, from the CCC, would apply to your example, but, as far as grave matter goes; CCC:
The obligation of the Decalogue
2072 Since they express man’s fundamental duties towards God and towards his neighbor, the Ten Commandments reveal, in their primordial content, grave obligations. They are fundamentally immutable, and they oblige always and everywhere. No one can dispense from them. The Ten Commandments are engraved by God in the human heart.
2073 Obedience to the Commandments also implies obligations in matter which is, in itself, light. Thus abusive language is forbidden by the fifth commandment,* but would be a grave offense only as a result of circumstances or the offender’s intention.***