Yay, I won £50

In the words of Victor Meldrew 'I don't believe it' but in a nice way. I never win anything!
A few weeks ago I emailed some green tips to this site http://mumandworking.co.uk/share-it-may I'd forgotten all about it and when I sent the suggestions I didn't really register that it was a competition so I was over the moon to get an email today telling me that I'd won! Yippeee!
So now I have a dillema, should I donate it to a worthy cause or selfishly blow it on things for myself? As it's money that I wouldn't have had I feel that I should donate it but another part of me thinks that doing that would be unfair to hubby as he is the breadwinner and he might be cross if I just donate £50 and then ask him for money for new shoes etc.
Help!!