Final answer:
It is not permissible to sign a contract for a new house purchase while already under an existing contract without facing potential legal and financial repercussions.
Step-by-step explanation:
No, it is not permissible for the couple to sign a new contract while they are already under an existing contract for a house purchase. Depending on the terms of the first contract, they may face legal repercussions for backing out, such as losing their deposit or being sued for breach of contract.
A salesperson should not advise clients to engage in actions that would violate their contractual obligations. The decision to back out of a housing contract should be made with careful consideration and legal advice, as there may be financial and legal consequences.