Need this subs help

Hello and good morning Reddit, just a quick question about Chapter 1. Ive been stuck on the ice cream moment and have been trying to make sure what it means for a while and it’s kind of racking my brain- i think I just don’t get social cues. Can anyone in this sub help me and clarify? I feel like the wording of “now it’s not eligible for return” is what’s tripping me up.

Did he do that that because she already ate a bit of the ice cream he bought her (the chocolate cup) and is trying to make a point to say you can’t return what is eaten? Is he feeding her his own and basically saying “no refunds”?

Any help appreciated, thank you.