Marriage deposits

What is the name of your state? PA

I was engaged to be married this fall. I have known this girl for 7 months, got engaged after 5 months. Her parents were making all of the deposits for everything. I then realized that we jumped into this too soon, now her parents want me to sign a promisary note to pay back all deposits they made in full. My question is, am I responsible for paying back everything to her parents?

No, not at this time. However, a court can and will most likely find you partially responsible should the parents file.