What is the relationship between Valentine and Angelica in Love for Love by William Congreve?

In the play, Valentine and Angelica are in love with each other; one can say that they are romantically inclined towards each other. For his part, Valentine is a libertine who enjoys a lavish lifestyle. However, his opulent lifestyle is supported by extreme debt, and he's constantly beset by creditors.
In order to extricate himself from his predicament, Valentine has to consider signing over his inheritance to his younger brother, Ben. In exchange for doing so, Valentine has been promised four thousand pounds by his father, Sir Sampson Legend, in order to pay off his delinquent debts.
Yet, Valentine isn't too enamored with the idea of signing over his inheritance to Ben. He tries to maneuver circumstances to get Sir Sampson to change his mind, but the older man is adamant about the matter. Valentine even tries to pretend that all this pressure has caused him to lose part of his mental faculties. For his part, Sir Sampson thinks that Valentine is playing a trick on him in order to escape signing the deed of conveyance. Sir Sampson is unconvinced about the validity of Valentine's plea of insanity.
In the meantime, Angelica, who is in love with Valentine, tries to maneuver matters to test Valentine's love for her. She pretends to flirt with Sir Sampson and finally agrees to marry him. When Valentine hears of the impending marriage (though a sham), he admits to Sir Sampson that he was never mad. He confesses that it was only a ploy to avenge himself for what he considered his father's duplicity towards him.
Valentine then agrees to sign the deed of conveyance because, apart from the deed, he's lost all hope of pleasing the woman he loves. He tells both Angelica and Sir Sampson that he's never "valued fortune but as it was subservient" to his pleasure and that his only pleasure in life was to please Angelica. He reasons that, if signing over his inheritance (which will in effect ruin him) will please Angelica (since she's marrying Sir Sampson), he will do so. Upon hearing this, Angelica is so overwhelmed by Valentine's generosity of heart that she tears up the bond.
This, of course, shocks Sir Sampson and he demands an explanation of her actions. Angelica responds that she's always loved Valentine, and upon trying them both, she's come to see their true natures for what they are. She then chides Sir Sampson for his "unforgiving nature" and resolves to marry Valentine. The play ends with Scandal, Valentine's friend, congratulating Angelica upon performing an "exemplary justice" in "punishing an inhumane father and rewarding a faithful lover." Based on the text, it is presumed that Angelica will eventually become Valentine's wife.