Sorry to hear that your attempts at a family day out were sabotaged in such a manner; I trust that the rest of the holiday was better.
A Catholic friend of mine recommends this site:
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as a good explanation of Catholic teaching. It seems a little simplistic, but is clear and gives us a good idea of what the Catholics mean.
In this is love, not that we loved God, but that He loved us and sent His Son to be the propitiation for our sins. (1 John 4:10)