An Elaborate Untrue Story

Okay, so I know I guess I asked for it when I had my kids so close together, but I didn't think it would start so early. I was in Wal-mart the other day with both kids and as we were checking out the lady checking me out asked if my kids were twins! Now given that Andrew was sitting in the buggy seat and Lillian was standing in the buggy, she couldn't tell how much bigger Lillian was than Andrew, but I figure this will just happen more and more as Andrew catches up to Lillian...so, it got me to thinking that instead of always saying, "No, they aren't twins, they are 16 months apart and yes, it was on purpose" I could come up with an elaborate story about how yes they are twins and some thing great to go with it...help me come up with my story! Then next time I'm asked which may be in weeks, months, or a year from now, I'll post how they react to it when I tell it to them! :) Thanks!