You always thought you had problems with being insensitive down there, however, it would appear you just jerked off too much and lost sensitivity, 2 months in chastity fixed that.
She said she had never cum from oral before. You thought you could prove her wrong so she bet you that you couldn't do it, and would be locked in chastity until you made it happen. Perhaps you were too confidant in your abilities. You thought you would
