Greg Stephens is essentially right that the problem is 'virginity' but I think it is a problem for the folk audience every bit as much as the Rugby Club audience.

I struggle to think of a SERIOUS folksong which contains the word 'viginity', (unless I've missed a very early carol to Jesus' mum)as opposed to simply 'virgin'. And even 'virgin' is not common. In serious songs it is maiden/hood/head, or something even more euphemistic or occlose.

I think folk audiences with any long experience know this intuitively and subconsciously. So when they hear the word they instinctively relax for what is surely somehow at some point going to turn out to be humourous.