It was rather sad to Amycus that he'd managed to follow the young snot and it didn't appear that he'd noticed. He would give young Alexander Greengrass III the benefit of the doubt though. Perhaps he had noticed and was simply manuevering them until they were somewhere that he could question why he was being followed without drawing a crowd. After all once could never be too certain who they were dealing with. Jumping the gun could get people in trouble. Not that Amycus minded a spot of trouble, but the Dark Lord might not be so pleased about it especially since he was interested in the brat.
So Amycus tailed him for a bit before he saw a little side alley up ahead that was darker and would give him a bit of privacy needed for a quick little... conversation. With that in mind he sped up a bit, his wand dropping into his hand from the holder to be held loosely. He debated whether he wanted to prod the kid into the alley. That could make the meeting tenser than it needed to be. He didn't like being courteous, but he also didn't like being at the end of the Dark Lord's wrath either.
With that in mind he simply passed Alexander, making certain to brush up next to him and gesture toward the alley. If the little snot tried to keep going and ignore him, well... That would leave it open to going down how Amycus wanted it to go down and that was decidedly not friendly. In the end it all came down to the boy and what he thought of it all to how things were going to pan out.