helleep helloop

My younger sister and I sometimes gchat, and the conversations usually begin with her popping up from the depths of "invisible mode" to say: "meep moop" or something phonetically similar.
This is our most current conversation:

Madrianne: meep moop me: peep poop

 Madrianne: veep voop

 me: leep loop

Madrianne: qeep qoop

 me: feep foop

 Madrianne: pleep ploop

me: fuh-zeep fuh-zoop

 Madrianne: madaleep madaloop

me: foongeep foongoop

Madrianne: haheep hahoopIeep haveep toop goop butoop Ieep willoop beep backeep ineep a littleep bitoop

me: timeep toop leep workoop

  foreep meeooop

  byeeep byeeoooop