One thing I’ve learned personally as I’ve matured is that a part of being well-rounded emotionally is having the capacity to accept the generosity of others, even when I am not in any form of need. Many times the person being generous (in this case, by buying dinner) gets more satisfaction and enjoyment than the person receiving the generosity. Pushing back against someone trying to be generous robs them of some level of happiness brought by being generous. So in any normal situation I’ve learned to just graciously accept when someone wants to do a kind gesture for me, again even when I am not in any sort of want or need. Obviously there are limits, like I’m not going to let someone ruin their own financial life for my sake, but that’s not what anyone here is talking about.