during the 2022 mpox (previously known as monkeypox) outbreak, in an effort to look at how sexual behaviour changes with age, so they could develop scientific models for sexually transmitted infections.Lead researcher Dr Julii Brainard, from UEA's Norwich Medical School, said: "Before this study, many models about sexually transmitted diseases assumed that everyone over a certain age, say 40 or 65, stopped being sexually active, or at least stopped having multiple partners."Or there might be an assumption that young people have the most sex."But the answer is more nuanced, and it partly depends on people's sexuality."Some 5,126 British adults were questioned, which included 3,297 sampled from the general population and 1,036 men who have sex with men (MSM) from Facebook and Instagram between 5 September of 6 October last year, with an additional 831 people responding to adverts on the gay dating app Grindr.Women who have sex with women, and other relationship types, were discounted due to the small numbers responding.Most people questioned had either zero or one sexual partner at any age in the preceding three weeks, with 65% of straight women saying they only had one partner in the last three weeks until they were 50, before a steep climb to no partners.Please use Chrome browser for a more accessible video playerSome 79% of straight women over 70 had no male partners in the preceding three weeks.Meanwhile, half of straight men in all age groups reported having one partner in the previous three weeks, but were more likely to report no partners as they got older.For heterosexual men over 70 who have slept with a woman in the last three months, half did not have a sexual partner in the preceding three weeks.That falls to 44% for straight men under 70.Having more than one recent partner, or partner concurrency, was found to be uncommon among the general population, but common among social media respondents.Some 42% of MSMs spoken to on Facebook and Instagram, and 52%.