>>715096695
It's basically a projection of shame present in Freudian anal-retentive people. People who like to "bottle up" their feelings as if they were gas.
When the child learns to excrete he experiences a mini-trauma because shitting when that young is a genuinely terrifying experience. Some of the children will learn to be anal-retentive or anal-expulsive as a coping mechanism towards this shame. Thus, this psychology eventually bleeds into their sexuality.
