Evelyn Ellis has written:

'Sex discrimination law' -- subject(s): Law and legislation, Sex discrimination against women, Sex discrimination in employment, Equal pay for equal work

'EC sex equality law' -- subject(s): Law and legislation, Sex discrimination, Equal pay for equal work, Sex discrimination in employment

'Public law of the European Community' -- subject(s): Public law, International law

'EU Anti-Discrimination Law (Oxford European Community Law Series)'

Porter Davis has written:

'Sex perversion and the law' -- subject(s): Sex and law, Paraphilias, Sex customs

He (or she) can be. The same-sex spouse of your sibling is your in-law. Likewise, the parents and siblings of your same-sex spouse are considered in-laws.

sex

No. There is no such thing as natural law.