A recent survey showed that Christians are less likely than the religiously unaffiliated to say causal sex, open relationships are acceptable but were equally split within Christians upon the topic of pre-martial casual sex.
A Pew Research Center Survey defined casual sex as "sex between consenting adults who are not in a committed romantic relationship" and asked respondents if casual sex between consenting adults is acceptable "regardless of whether they would do it themselves."
To this question, 62% of Catholics agreed while 56% of Protestants and 36% Evangelical Protestants agreed.
In contrast, a larger group of 84% of those who are religious unaffiliated said casual sex is sometimes or always acceptable. The religiously unaffiliated group included 94% atheists and 95% agnostics.
When respondents were asked about sex between unmarried adults who are in a committed relationship, more than half of Christians (57%) say it is sometimes or always acceptable.
Evangelical Protestants were least likely to find practices such as having sex on a first date, exchanging sexually explicit photographs with other consenting adults, and having an open relationship acceptable. An open relationship was defined by the Pew Research Center Survey as a committed relationship where both people agree it's acceptable to date or have sex with other people.
3 in 10 evangelical Protestants answered that it's sometimes or always acceptable for two consenting adults to exchange sexually explicit images of themselves whereas 7 in 10 religiously unaffiliated Americans answered so.
Church attendance played a significant role in the survey as well. 12% of the people who went to religious services at least monthly answered that it was always or sometimes acceptable to have sex on a first date whereas people who attended church on a monthly basis were more tolerant by yielding votes of 38%.