D. Pedro was shy, prude and proud.
He did not tolerate his Father's behaviour regarding women, and was much against his relation with Elise Hensler, whom D.Fernando finally married to have peace with old Infanta D. Isabel Maria, known for her extreme bigottery who nagged him for his sinful life.
OTOH Infante D. Luis, the sailor-prince, although one year younger, had a much vast experience with women which also exasperate prude D.Pedro who never cease to recriminate him.
One thing is true however: after D. Estefânia's death, D.Pedro contemplated the idea of re-marrying and father a son who would continue the dynasty.
Probably not to have his brother and his eventual descendants in the succession line.
The fact that he contemplated re-marrying, or so he let know of this intentions, makes one wonder how would he foresee his sex-life.
A second marriage without any children would seem odd for a normal healthy man, at a time where infertility was always the woman's fault.
