From "Emma: Episode #1.6"
[apologizing to Emma for deceiving her about Jane Fairfax
] You must consider exactly what position I was in. I had fallen in love with her at Weymouth - and yet I did not dare to address her openly. Had my poor aunt discovered the truth I should have been forced to renounce either Miss Fairfax or my inheritance. The latter I would have done gladly. By doing so I should have deprived the woman I loved of future wealth and position. What could I do but induce her to stoop to a secret engagement?