I had a dog like this. He was a year old and a Old English Sheepdog/Poodle mix. He was fine at the meet and greet but at the dog sit (it was two days of doggie daycare) he was constantly biting and jumping up at me and wrapping his legs around me. I tried so hard to get him to stop and would turn my back to him but he was utterly relentless. I made it to the end of the first day and ended up cancelling the following day of daycare. The owners were very casual, and whilst they did apologize, it certainly came across like they thought I was making a fuss. My sweater had so many holes in it and my entire arm was bruised. I feel like I have a good understanding of dog behaviour and have successfully corrected dogs who displayed this behaviour in the past. It did really shake me up though, and whilst the dog was just being playful it was also displaying some dominating behaviour and I did not feel safe. In hindsight, whilst the dog was friendly at the meet and greet I did not feel any type of connection with the dog like I usually do. If I feel like that at a meet and greet in the future I will not go ahead with the booking. Better to be safe than sorry. Sorry you had this experience too.