Shalom uverachah and thank you.
Reuven approached Shimon and asked him to find properties they could buy together, with Reuven providing most of the money and Shimon, who would be doing the legwork, taking most of the profit.
Shimon found a property and told Reuven why he thought it was a good deal and they bought it. One reason Shimon liked it is that there was a possibility of buying the property next door and the two together would be more valuable.
A few weeks later the property next door came up for sale and Shimon is making efforts to buy it (and told that to Reuven) but hasn’t managed to get it under contract yet. Meanwhile, Reuven told Shimon he wants his money back. So Shimon said, “Lets sell the property.” Reuven agreed.
Shimon now wants to put the property next door under contract for himself alone, for the same price he bought the first property for, and put down a small deposit from his own money. He would then sell the contract for the second property together with the first property, asking the same amount for each, but he would only give Reuven a percentage of what he gets for the first property and he would keep the profits from the second sale for himself.
The question is: does Shimon have any chiyuv to his partner (who has already stated that he wants to get out) to include him in the purchase of the contract of the second property?
Since Shimon expressed explicitly that he wants his money back he is saying that he wants to end the patnership, Therefore you have no commitment to him as far as the contract of the second property. Obviously Shimon cannot use any of Reuven’s money for this deal.