In many jurisdictions, legislation reflects, retains and reiterates heteronormative two-parent models of family. Lesbian and gay individuals and an increasing number of heterosexual individuals who choose to parent outside the paradigm of the conjugal couple relationship find neither their interests nor the welfare of their children is sufficiently protected in law. This article is based on the findings of two empirical research projects investigating the procreative autonomy of lesbians and gay men in New Zealand and the United Kingdom. It focuses on collaborative co-parenting families formed by lesbian couples and gay men, with reference to the allocation of legal parenthood in these kinds of families and case law across both jurisdictions. Two such families are introduced. Attention is drawn to the ways the law hampers these families’ preferred parenting arrangements. The article highlights the need for legislative change. It concludes that a more flexible, inclusive concept of legal parenthood that honours the intentions of those involved in these arrangements would potentially benefit all people interested in non-traditional parenting.