Guys can be soo shallow!
Just cuz a girl is wet does not mean she is enjoying sex, or that your any good, some women are just naturally really wet. Plus "**** buddies"( I hate this term!) lack the one thing that is so essential for arousal and participation...feelings. Several studies show that sex is less enjoyable when there are no feelings involved. A guy once told me that him and a girl( not really his gf) were trying to have sex, and she just could not get him aroused and she was supposedly really "hot", I theorize it was cuz there were no feelings, nothing beyond lust(if even that was present) , so while maybe they did have sex at other times...chances are he was just horny and she had nothing to do with it, plus studies show couples in love generally enjoy sex more then those just having affairs, or those with multiple partners.
And since you know you cannot see yourself,
so well as by reflection, I, your glass,
will modestly discover to yourself,
that of yourself which you yet know not of.