I am sorry to ask the same topic question again, but I have to ask it again.

Family agreement is not binding except for some cases.

(Below is the answer I've got from tutoring help in Course Hero)

In social and domestic agreements the law raises apresumptionthat the parties do not intend to create legal relations:

....This presumption may be rebutted by evidence to the contrary. This evidence may consist of:

Awritten agreement:

Where the parties have separated:

or where there is a 3rd party to the agreement:"

Dolph is a commerce student. His uncle Jimbo offers him $250 if he

passes COMLAW 101. Dolph accepts. Dolph studies hard and passes with a

B+ grade. When he tells Jimbo, his uncle is very pleased. "Well done. How

did you do in your other subjects?" he asks; "I'll give $50 for each subject

you passed."

"Thanks very much," says Dolph who tells him (truthfully) that he passed all

of the other three subjects he was studying. "Outstanding. Good job," says

Jimbo.

Jimbo's rental property investments have recently been hit hard by the tax

reforms in the Budget so he refuses to pay Dolph anything.

How much does Jimbo have to pay Dolph, and why?

Then, in the scenario above, as there is no written agreement and there is no 3rd party to the agreement, so I conclude that Dolph has to pay nothing for it.

However, in the lecture, it says although it is a family agreement Jimbo has to pay $250 to Dolph(We don't consider $200 because they are all past consideration), because there is an intention to create legal relations. Then how should I understand this?

I know this should be asked to a professor, but it is strange to say, I feel shy for it.

Can you explain to me, please?