This is easy...

You got a guy on a MTN bike.. chugging along and he see you... Mr. Sporty Younger Roadie Dude so he feels the need to pass you, and he does, but its hard then to keep a pace above where you are cruising so you hang behind him like you said... he is humilliated when he realizes that you are drafting so he pulls the smarty smart-smart bullschidt on you.

Age? I dunno.. I am 35 and wouldn't play this game with you cause I don;t feel the need to .. wait a minute... I might just try to overtake and pass you... even use you as an excuse to up my pace and keep you off my tail... haha... but it wouldn't have to do with your age...

... it would be based entirely on the level of flamboyancy of your jersey.

cAPS