N.Y. Domestic Relations Law § 172: Co-respondent as party

§ 172. Co-respondent as party. 1. In an action brought to obtain a

divorce on the ground of adultery the plaintiff or defendant may serve a

copy of his pleading on a co-respondent named therein. At any time

within twenty days after such service, the co-respondent may appear to

defend such action so far as the issues affect him. If no such service

be made, then at any time before the entry of judgment a co-respondent

named in any of the pleadings may make a written demand on any party for

a copy of a summons and a pleading served by such party, which must be

served within ten days thereafter, and he may appear to defend such

action so far as the issues affect him.

2. In an action for divorce where a co-respondent has appeared and

defended, in case no one of the allegations of adultery controverted by

such co-respondent shall be proven, such co-respondent shall be entitled

to a bill of costs against the person naming him as such co-respondent,

which bill of costs shall consist only of the sum now allowed by law as

a trial fee, and disbursements.