Gas Pump Scam Attempt

What is this scam called?

I was getting gas at a travel center, and a seemingly nice couple said hi. I said hi back, then came the ask. Hey, if we give you cash can you let us pump gas from your…

Me: Nope!

Them, but you’re already pumping …

Me: Nope!

Them, but it won’t cost you …

Me: NOPE!!! I am done and I shut off the pump and get ready to move to parking at the travel center to get chips and a drink to continue my trip. I hear them talking as though I am being unreasonable, but after their third attempt they clearly gave up

Don’t fuck with my money