Neighbors are too much

I have neighbors that have a little boy who is around age 6-7. He constantly makes my dad buy him McDonald’s, and my dad is a big pushover and does it. I feel like my neighbors parents purposely push him off on us and want my dad to pay for his lunch so they don’t have to. Recently, my dad is out of work due to an injury at work, and his work is giving him a hard time and not giving him any pay while he’s absent. The boy comes over all the time still begging for McDonald’s and my dad keeps politely declining him but he keeps coming back. I feel like my neighbors use my dad a lot (there are a lot of other things they do) and they know that he has a soft spot for their son.