"Reply when I feel like it."
Means: "I'll
never reply. I never feel like it."
Usually the response a guy gets when confronting a female on why she doesn't reply to his messages (and try to
work things out).
Can also be undertext if they tell you "I'm busy." which means: "I
don't feel like it."
Jason: "I want to fix things, but you
never reply, you keep saying you're
busy but you're always
texting your friends". Sonya: "I'll reply when I feel like it."