If there is an agreement between the two parties and both are truly trustworthy, why not? One of the benefits of Bitcoin is as a means of payment, especially globally. This makes it easier to pay for certain transactions. Although indeed in some countries such as India, the use of Bitcoin is prohibited, right? However, if it does not involve the government and there is also an agreement between the two parties, then I think it will not be a problem. As long as we don't have to brag about telling other people about the transaction.