A person that can twist any subject or conversation adding in filthy comments, toilet humour and sexual connotations.
In the office today there were two birds on the window ledge, a colleague said they were Swallows, immediately "Filthster" said "I love a bird that swallows. While in the canteen making an innocent cup of tea Filthster walked in and said "may I squeeze your bag sir" followed by "do you want me slip some man milk in there".
by DaveySmith April 12, 2017