Heya! No problem, in the descriprion here, at the end there is a walktrough(spoilers), press on the little arrow to expand, there is the way to get The bad end no.3 :D
Ohh, you have to unlock the option "I like you" , to unlock the option, before you had to choose between "I love you too" and "Whatever...", you need to choose "Whatever..." option, then you will be able to see the option "I like you too" later (Sorry for replying so late, I didn't got notification :( )