We were out at the park today and Blodwen and Llewelyn whilst offlead were approached by an offlead Bull Mastiff dog. We have seen this dog before at the park - he had tried to mount Blodwen then and that time I quickly moved Blodwen on (she was on lead) and went separate ways quickly.
My two were playing together and the dog ran across the length of the park. He kept sniffing at Blodwen's rear end, she always rolls on her back whenever she receives attention like this from dogs, but today she jumped back up after a few moments with a little yelp and snapped a little - and this happened a couple of times as this dog persisted.
Then the Bull Mastiff turned to Llewelyn, sniffing his behind, and would NOT leave him alone. He kept trying to mount Llewelyn, and Llewelyn was having none of it. Llewelyn jumped and ran towards him, barking every time. He didn't touch the dog but barked loudly at him. I have never seen either of my cockers behave like this before in such a defensive way. The Bull Mastiff didn't react, just waited until Llew stopped and then started trying his luck again.
His owners eventually approached and thought it was hilarious, didn't try and stop him and just said 'he's trying to play'. Meanwhile, both Blod and Llew looked increasingly stressed, tails between legs - Llew was barking, Blod just ran away, very unlike her, she normally loves a run and a play with other dogs.
I took my pups off away from this dog swiftly but I wondered whether I did the right thing in letting Llew behave like this. In one respect, I wanted Llewelyn to learn to be able to tell this dog off by himself, and in a way, felt quite proud that he stood up for himself because Blod has never done this and there have been times where I wish she had, but I also wanted to protect him from this dog and felt really angry at his owners. In another respect, felt glad this dog didnt react to Llew's barking otherwise it may have escalated into a bigger fight.
I just wish walks could be simple (and they normally are) - I would appreciate any thoughts or guidance on handling a situation like this in the future.