John Mayer was Jennys paid escort so she would have a date for the oscars. He did his job and his contract won't allow him to blabber on so its a done deal.
He likes em young and hot.
Jenny doesn't fit this profile. The douche Mayer is probably glad to move on and be as far away from Jenny (his mother) as possible.
In 99% of cases, Twittering is just randomly bragging about your unexceptional life. In the case of John Mayer, it's just bragging about an unexceptional life largely consumed with dating a fugly dinosaur.