Turning On Those Who Support Him

A person who turns on you when you're nice to them, when you are supportive of them, OR when you seek support FROM them is reacting negatively to specific things:
support and connection.

They seem to react when you seek their support, and they also seem to react negatively when you give them support, whether it's right away or soon after.
The common denominator is "Support".

They might perceive support itself as a threat, possibly an attempt to control them or dominate them, or as a way to show superiority, elitism, authority, or entitlement.

(They might have had a narcissist or two in their childhood who disguised control as support, or humiliated them when they either gave support to others, or sought it for themselves.)

Therefore, it's not possible to have a mutually supportive relationship with them, which means one can not have a "real" peer-relationship with them at all. Every time you seek support from them, they turn on you; every time you show support for them, they turn on you... There's not much left in the way of personal connection.

You might be able to work with them, do some activities with them, as long as it was kept on a less personal, more formal level. But intimacy or even close friendship might not be possible, since both require mutual, genuine, and open supportiveness.

One such experience a person related about this was when he inherited a rather large sum of money, and he offered to give his best friend some of it, especially in light of his friend's immediate hardships that he seemed very depressed and anxious over. Instead of his friend accepting the money gratefully or even refusing it politely, his friend reacted with disdain and disparaging comments about the man's money-sense, and then started giving him financial advice. Of course the man was shocked and hurt by his friend's very rude reaction.

After a while it became clear that the "friendship" had been based on some kind of "leader and sidekick" scenario that his friend held regarding the two of them, and when the "sidekick" friend ended up with more money, the scenario didn't hold water anymore, and so his "best friend" turned on him. HE had to be the one who was supportive and who knew "better", and the arrival of the money exposed the agenda, which the "sidekick" man was completely unaware of (but had been confused about for years).

The "support" and "advice" that the man's "best friend" had been giving him all these years had just been a display of control and ego. And now he understood WHY, when he ASKED for help and support, his "best friend" would either be suddenly too busy, or too broke, or too sick to help.

And he also understood finally why his "best friend" would somehow avoid and turn down any direct support he offered to contribute, even volunteering to repair a damaged section of a kitchen wall, or volunteering to babysit his kids.

The "best friend" had to be IN CHARGE of ALL "support" between them, and if he wasn't the one INITIATING IT, he would shut it down somehow, or completely take over so he would end up being the one 'in charge'.

Because it was never about actual, genuine "SUPPORT" or mutual connection, it was about control, power, and "status".