I want to get a six pack but not going to gym?

im 17 and i only have a 2 pack (i know how lame) and i wantto get a decent body to impress a girl i really like and i dont like going to the gym cus i dont feel comfortable working out in front of people and is there eny ways of gettin one at home atm im doing like 50 sit ups and 50 crunches a day and also the bicycle sit up thing