The last girl I dated, I met socially. And the main reason I wanted to date her was because of her wonderful personally, not because of her physical attractiveness. So it is wrong to say something across the board when it works for some people. But, in the OP’s brother’s case, it just seems to be for the fun of it without long-term thoughts in mind, which will either fizzle out or become more of a problem, which can be solved through different ways, depending on the situation.
