No offence Gray, but it might be that they are just riding faster than you are so will pass you anyway, not that they are judging you for what you ride and expect you to follow them for a race etc.
When I'm out and about, if i come up behind another biker, regardless of what they are riding, if they are going slower than my pace at the time I will pass at the first possible chance ( though will usualy acknowledge them, unless I'm seriously concentrating ;) ) but if they are on the same pace as me I'll follow for a blast until our paths seperate

!
Oh and I wave at everyone, from sports bikes to chops and even scooters, in the hope that they move up to bigger bikes rather than go the way of the corsa

, Hell, I even wave at quads ;)