I am unsure of how well a surprise this will be, but.. Perhaps these will suit you well.

[Digging around in the bags, Dimitri pulls out a pair of simple and rather blunt wooden daggers. They of course can't be anything like the real thing, but they do well for jabbing, in his experience, and are weighted enough to give someone a headache.]

[Ask him how he knows.]

[Or just accept them as he holds them out to Astarion.]

Please let me know how these suit you. They will certainly not last the whole night, but I imagine they will prove useful.