Its time to move on! Four generations is nothing to sneeze at, you've had a pretty good run.
Problem is it was going so well (bugs notwithstanding) – I'm still enjoying them… But I'm tired of multiple births, I have to admit, and I'm peeved at the relationships vanishing on me because I spent a lot of time building those up (I like people who get on with each other :D).
Oh well. Le roi est mort, vive le roi, I guess!