Time off work, an increase in parties and a more relaxed attitude can lead to sexual health problems over the Christmas period.
This is according to comments from Jason Warriner, clinical director at the Terrence Higgins Trust.
Mr Warriner said: "People become more relaxed over the Christmas period and chilled out.
"Depending on when Christmas and New Year falls you could have a good week to ten days off work so people may drink more and opportunities may come up to have a one night relationship with somebody."
The comments follow research conducted by the Daily Mail, which revealed that almost half of British women in their 20s have had a one-night stand.
A similar number of women in their 30s and 40s also reported having had a one-off sexual encounter.
Women in their 40s were the least remorseful, with three-quarters stating that they have no qualms about the experience.
The paper did not report any figures concerning men who had had one-night stands.
Independent advice on private healthcare