My step grandmother was involved in something almost exactly like this. A man sent her a picture who looked just like the Dos Equis guy...completely fake but she just couldn't see past it. He said he was some kind of contractor or some crap, and that he was helping poor children in Africa and building homes for them. He would talk on the phone to her but when other people wanted to talk to him or when she wanted to talk to him around her family he was always busy or away. Eventually he wanted money for airfare. She realized it was a scam and ended up with a broken heart....classic scam OP. Tell your aunt to block him, block his number, everything!!
Sorry about your aunt :( It's really a sad situation :(