Hi, My Karleigh has been doing that since she was a baby, now at almost 3, she does it alot more also, Upon comming home is the worst time, like you said i think the longer they hold it the more they go, She also has a big crush on my daughters BF so when he comes over she really does it, I hope everthing is ok and i will watching for your post update.,BTH I have asked my vet about this many times, and always get the same answer, its normal
good luck
