Poor Bailey, he does look so sweet. I think the others are just jealous...
Seriously tho, my males (one an Irish Wolfhound, the other a Neapolitan Mastiff) had the same problem and always w/other male dogs, even after they were neutered.
I had to keep them leashed and when other dogs approached, I asked the owners to keep a tight reign on their pets when I saw "the stance" that was being taken by other males. Both my boys were very friendly and never initiated fights and both would back away instinctively unless they thought I was being threatened. I would ask, then if they didn't I'd remind them of the leash laws.
Also, when my Neo was playing w/other dogs and I saw any play getting out of hand, I'd would initiate the retreat and make him lie down/leave.
Hope that helps some.