Why does Touchstone marry Audrey in As You Like It?

This is rather a baffling question. In Act III scene 3, when
Touchstone tries to marry Audrey as quickly as possible, he calls her a "slut," recognising that
she has had many relationships before, and also identifies that she will probably be unfaithful
to him after their marriage. However, nonetheless, he continues to press ahead, trying to get
married as soon as possible. From what we can infer, it appears as if his own lust seems to be
acting here. However, overall, we can identify that the marriage between Touchstone and Audrey
acts as a kind of anti-Romantic coupling that acts as a foil to the other relationships in the
play. Their marriage is a travesty of romantic love and marriage, and the way in which Touchstone
uses his education and language to further his lustful advances on Audrey stands in direct
contrast to the relationship between Rosalind and Orlando.