Remove the skin and seeds from both types of melon and cut the flesh into pieces. Wash the rest of the fruit, pat it dry and then cut it – except for the raspberries which you will leave whole – into pieces as well. Put all the fruit in a bowl with the sugar and vanilla seeds (slit the pod open lengthwise and scrape them out using the flat tip of a knife) and stir delicately. Add the juice of the lemon, the wine, and the thyme and mint leaves. Leave in the fridge to rest for about half an hour before serving.