The phrase “no backsies” is an informal expression used among friends or playmates during games or activities to establish a rule or agreement that once a decision or action is made, it cannot be undone or taken back. 

Essentially, it means that there are no do-overs or second chances allowed. It is often used playfully to enforce fairness and discourage any attempts to change or revoke a decision after it has been finalized.

Example sentences 

1. “We made a deal, no backsies!”
2. “Remember, once you agree to it, there are no backsies.”
3. “I’m taking this toy home with me, and there are no backsies!”
4. “No backsies on that decision, it’s final.”
5. “We shook hands, and you know what that means—no backsies!”
6. “You can’t take back your promise now, no backsies allowed.”
7. “Once you’ve signed the contract, there are no backsies.”
8. “No backsies! You can’t change your mind after we’ve already started.”
9. “We agreed to split the cost, no backsies.”
10. “No backsies on that bet—you lost fair and square.”

More sentences with the phrase “no backsies”:

1. “You borrowed my favorite book, so no backsies! Return it when you’re done.”
2. “No backsies on that dare. You have to follow through!”
3. “Once the secret is out, there are no backsies. Prepare for the consequences.”
4. “You can’t undo your actions now—no backsies allowed.”
5. “We made a pact, and there are no backsies. We stick together.”
6. “No backsies on sharing your dessert. You promised!”
7. “You sold me your old guitar, no backsies. It’s mine now.”
8. “We agreed on the terms, and there’s no room for backsies.”
9. “No backsies on revealing that surprise party. It’s out in the open now.”
10. “Once the decision is made, there are no backsies. You have to live with it.”

Backsies Synonyms 

Here are some synonyms for “backsies”:
Reversal of fortune
Reversal of decision