So sorry for the trouble! This is on our list of possible improvements for the future – I can’t say exactly when it’ll be added, but we know it’d be a useful improvement. In the meantime, our apologies for the inconvenience!Gianluca Cacace commented
I would definitely like to have this feature, as I normally pay also for my partner during holidays and trips. It's quite annoying forcing all the group members to put 2 shares on me and 1 on them every time.