How do I lose around 10 pounds fast?

So in around a month I'm going to be having quite a summer ordeal, my bestfriend and my girlfriend are going to be returning to the state I live in so I would like to lose some of my winter weight... How do I lose around 10 pounds, the quicker the better, without anyone noticing? My parents complain if I work out in the house and I don't trust my neighborhood enough to do daily walks, I take a Karate cl but it mostly trains on muscles, coordination, memory and a little bit of cardio, not weight loss. Is there a possible way I could lose some weight without being yelled at by my parents?