Am I being evil?

When we first got engaged my FIL's offered to pay for flowers, limo, etc. As time passed it was obvious that they weren't going to pay. My fiancee and I told my parents that we would cover what they were originally supposed to. I am very fortunate and my parents said absolutely not, they would take care of everything.

The one thing the IL's stuck to was the rehearsal dinner. I put down the $50 deposit to hold for the night and now my FMIL wants to send me a check. It's only $50 but out of spite I want to actually take it from her. I'm so bad....