In The Bride of Lammermoor (Chapter V), we are informed that the heroine  placed certain restrictions on their intercourse,  a limitation that might have been more usefully set in that same author's Rob Roy (Chapter VII) where we are told of the chance that the narrator and Miss Vernon might be  thrown into very close and frequent intercourse. 
( ( In ( ( The Bride ) ( of ( Lammermoor ( -LRB- ( ( Chapter V ) -RRB- ) ) ) ) ) ) ( ( , ( ( we ( are ( informed ( that ( ( the heroine ) ( ( placed ( certain restrictions ) ) ( on ( their intercourse ) ) ) ) ) ) ) ) , ) ) ( ( ( a limitation ) ( that ( might ( have ( been ( more usefully ) ) ) ) ) ) ( ( ( set ( in ( ( ( that ( same ( author 's ) ) ) ( Rob Roy ) ) ( -LRB- ( ( Chapter VII ) -RRB- ) ) ) ) ) ( where ( we ( are ( ( told ( of ( the chance ) ) ) ( that ( ( ( ( the narrator ) and ) ( Miss Vernon ) ) ( might ( be ( thrown ( into ( ( very ( ( close and ) frequent ) ) intercourse ) ) ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (NP (DT The) (NN Bride)) (PP (IN of) (NP (NP (NNP Lammermoor)) (PRN (-LRB- -LRB-) (NP (NNP Chapter) (NNP V)) (-RRB- -RRB-)))))) (PRN (, ,) (S (NP (PRP we)) (VP (VBP are) (VP (VBN informed) (SBAR (IN that) (S (NP (DT the) (NN heroine)) (VP (VBD placed) (NP (JJ certain) (NNS restrictions)) (PP (IN on) (NP (PRP$ their) (NN intercourse))))))))) (, ,)) (NP (NP (DT a) (NN limitation)) (SBAR (WHNP (WDT that)) (S (VP (MD might) (VP (VB have) (VP (VBN been) (ADJP (RBR more) (JJ usefully)))))))) (VP (VBD set) (PP (IN in) (NP (NP (NP (DT that) (JJ same) (NN author) (POS 's)) (NNP Rob) (NNP Roy)) (PRN (-LRB- -LRB-) (NP (NNP Chapter) (NNP VII)) (-RRB- -RRB-)))) (SBAR (WHADVP (WRB where)) (S (NP (PRP we)) (VP (VBP are) (VP (VBN told) (PP (IN of) (NP (DT the) (NN chance))) (SBAR (IN that) (S (NP (NP (DT the) (NN narrator)) (CC and) (NP (NNP Miss) (NNP Vernon))) (VP (MD might) (VP (VB be) (VP (VBN thrown) (PP (IN into) (NP (ADJP (RB very) (JJ close) (CC and) (JJ frequent)) (NN intercourse))))))))))))) (. .)))
They had restrictions about how they may have sex
( They ( had ( restrictions ( about ( how ( they ( may ( have sex ) ) ) ) ) ) ) )
(ROOT (S (NP (PRP They)) (VP (VBD had) (NP (NP (NNS restrictions)) (PP (IN about) (SBAR (WHADVP (WRB how)) (S (NP (PRP they)) (VP (MD may) (VP (VB have) (NP (NN sex)))))))))))