i would make the same face as Ummal in your (Laxus_Dreyar's) pic/post, and just look at'em until they apologise, then throw it away, and find some kind of meat ta eat. >:S
Like Dray said- don't waste ice-cream, i'm likely to be ill anyway so what's another couple thousand germs?
However if it were my son eating the ice cream, i would stop him, run after the bloke who sneezed/coughed on it and politely say "here, あなた really wanted my sons' アイスクリーム after spreading your germs on it" hand it to him and then go buy my son another one.
"Nigga...you serious?" *pulls out USAS-12 Automatic* "Coughing in my shit I see. あなた know, 'cough' is synonymous with 'pull trigger'. I think I feel a cough coming. または あなた could buy me more. Your pick."
Me: *twitches eye* Umm, *fake smiles* Watch out where あなた cough sir. *throws Ice Cream* (buys another one) Guy: *sneezes on My Ice Cream* Me: DAMN IT! *smashes Ice Cream on his face*