Oliver was smart and that's why he immediately discovered Andrew's intentions to propose the lovers' pact. Marie on the other hand, felt only joy in knowing that she would be eternally united with her beloved, so they both agreed.
Seeing that they had both accepted Andrew began to explain to them how to perform the lovers' pact, "It's really not complex. The ritual consists of 3 simple steps. The first is to pledge your love before the moon, the second step is to pledge your love before the sun and the last step is to pledge your love before the world."
Despite Andrew's explanation, no one in the office understood how to do what he said, but Andrew knew that, so he went on to explain, "There are several types of lover's pacts, but the most convenient for you is the one under the domain of Eros."