We're having groups of family friends over this weekend to celebrate summer and the boiling weather (I know its unbelievable we finally got some sun in the UK). We usually alternate between who has to host however we haven't hosted in over 3 years and so it would be very unfair for the responsibility to not land on us. As much as we appreciate these friends, they usually leave a mess (spillages, dropped food etc...). Would it be unreasonable for us to request a small deposit (almost like a ticket haha if you think of it that way) before they arrive. The money will be returned provided they don't leave a huge pile of dump (like they unfortunately sometimes do)? My aunt had a wedding in the US and guests were asked to transfer a deposit on the same basis. Everyone was happy about it, and the venue was left in spotless condition as everyone collaboratively cleaned up.