There's a famous Hollywood quote that applies to Charlie, "I don't pay them to have sex, I pay them to leave." Paying means no commitment, no alimony.
I totally agree however, Charlie thinks they love him and want him because he’s such a talented desireable man. he buys outrageous gifts (thanks Charlie the enonomy needs that!) but that is the only reason these women are with that snaggle toothed loser