Oh he sounds very dodgy.

I’ve come across (not me personally but colleagues) men who don’t regard social media/dating apps as cheating on their partners. Sounds like his moral code might be very different to your friend’s. I feel very sorry for the fiancée.

As an aside I wouldn’t let someone I don’t really know pay for my meal, I’d do this if I really knew someone and they were a friend/we took turns paying. It keeps things neutral and you don’t owe anything to anyone if you pay your own bill, that’s my rationale behind this.