Ha ha! How strange! As far as the reason as to why she does this we may never know. One thing that I can think of is the timing. Does your girlfriend come over at a specific time every day? Dogs are creatures of habit and if she is pooping at 5:02pm everyday at the same time your girlfriend gets there then it may just be her poop schedule. I would recommend taking her out to potty more often and praising her when she does. Does she give you any signal when she needs to go? My childhood dog never gave an indication that she needed to potty so we started asking her and then taking her outside. Soon she caught on that when we asked her we were giving her a command to go outside to potty and she would run to the door. I understand you feel a little guilty about putting her in her kennel when you go out however, for this particular reason she probably should be put in it until her potty habits are under control. At this point you may as well start the potty lessons over again. I know it sounds frustrating and believe me, I feel your pain. We had to do the same thing to my childhood dog. As soon as she gets up take her out, when she finishes eating take her out, before you go to bed take her out and when you leave her alone, even if it's for 10 minutes she goes in her kennel. I know it seems harsh but when kennels are used correctly (never for punishment) dogs generally love them. My dog is 9 years old and she puts herself in her kennel when she is tired or wants to be left alone and it is great for her! I highly doubt this has anything to do with her now liking your girlfriend by the way!

Border collies and whatever mixes they come in can generally be high energy and highly intelligent dogs and for that reason they are excellent herding and working dogs. Usually this breed enjoys learning new tricks and getting lots of exercise. If you feel like you are too dominant with toys maybe you should try playing fetch with her. It can be a great way for her to burn some energy off as well. Just curious too from reading you post, does she live in the backyard by herself or is she outside for 2 hours a day for play time? If she is outside all day by herself she may be getting bored and lonely.Dogs don't get as much stimulation and exercise being alone in the backyard as much as we would think and lack of these things can cause destructive behavior. All dogs by nature are pack/social animals meaning they depend on each other for comfort, socialization, stimulation etc and they are with their pack all the time. You and your family are her pack. If she has 2 hours a day of play time in the backyard then she may need more activity. Walk, runs, dog parks and doggy daycare and training are great ways to stimulate her mind and curb unwanted behavior. I would highly recommend investing in a good training class. Unwanted behaviors are the number one reason dogs end up in shelters. It's amazing how much training and effort can change the life for the better for you and your pet, it's also a good way to bond. A good trainer can help you communicate with your dog better. I hope this helps, unfortunately there is no one best and easy solution.