The author of a ‘flawed and misleading’ study on gay parenting has made a series of ridiculous claims about same-sex marriage.

Mark Regnerus claimed that, as a result of legalising same-sex marriage, straight men would begin demanding more anal sex, and open relationships from their partners.

The University of Texas professor made the claims in a clip posted by Jeremy Hooper of Good As You.

He said: “If gay marriage is perceived as legitimate by heterosexual women, it will eventually embolden boyfriends everywhere, and not a few husbands, to press for what men have always historically wanted but were rarely allowed: sexual novelty in the form of permission to stray without jeopardizing their primary relationship.”

He goes on to say that the “normalisation of gay men’s behaviour”, would mean an increase in the “practice of heterosexual anal sex.”

The Regnerus study, published in July 2012, was titled “How Different Are The Adult Children of Parents Who Have Same-sex Relationships? Findings from the New Family Structures Study”.

Regnerus compared the lives of children raised by parents gay relationship, of any length, with those who had grown up with straight, married parents. The first group appeared to be more likely to be in therapy, have extra marital affairs and experience other negative outcomes in later life.

The study has already been criticised for failing to receive “ethical and appropriate professional peer review”, and for focussing on children whose gay or bisexual parents had separated, but surveying children whose straight parents had stayed together.