I agree it's not at all the case in a LTR but in the 'men sew the seed, women nurture it' sense you could say that women can become more biologically/emotionally attached after sex than men..

That being said I don't really believe its true in modern society, but you can kind of validate his statement to a point, it is narrow minded though.

Never the less, bold statement on a forum full of heart broken guys lol