My 18mth, Molly, has started to submit to male dogs. She is so pleased to see them as they walk towards her, she shows off, jumping in circles or walking on her tummy, but when the dog is right up close, she lays on her side or backs away slightly. With her best male friend, she play fights & during the play lays on her side, then gets up & returns playing.  Sometimes she will cry when they walk away. Molly is in between seasons at the moment, not due until April. I thought it may be a hormone thing. I don't find it a problem, but I'm worried that Molly is suffering. This behaviour has only been in the last couple of months.