after Obama made fun of him at a state diner iirc

It's guess that even for Trump there's probably a fine balance between:

• wanting to be seen as a 'winner' by associating yourself to 'winners'; and
• disdain for critics that tarnish your personal image, since that would make you be seen as a 'loser'.

And I'd pretty sure Obama making a joke about Trump hijacked the later in Trump's mind.

Being more realistic through, is that this winners/losers is really an observable tendency in Trumps' decision making process, however the fact is that it's obviously not a binary decision and there's nuance to It, since the human mind is usually not 'rational', not immutable, and also not necessarily consistent, in its decision making process, over time.

not the same as hanging out