When an attraction of the opposite sex crosses the line and becomes annoying.
ie too many phone calls, emails, facebook "likes", texts, accidentally leaving personal articles ones house, ect.
When you buy a new puppy it follows you around...all the time!! No matter if you yell at it, put it in time out or make it smell its own urine it left on your living room floor, 5 seconds later it will forget and love you more than ever.
Dude 1: Holy!! This is the fifth text I have gotten from this chick and its not even noon!!
Dude 2: Didnt you just meet her last night???
Dude 1: Yes and I havent responded to one of them. She's already puppydoggin'!!!