Similar thing with men in Asian countries such as Thailand, The Phillipines etc - old men and young women. Many for sex and others get married and often bring the wives back.
Either way they look odd when it's a partner in 20's and a partner in 60's - grim, desperate and weird looking, buying a partner and everyone knows it. People say if they are both happy, but are they really, if money wasn't an issue, would they really pick that 'partner'.