I was wondering if you could shed some light on "thighing" and is it true Aisha used to wash the semen off Muhammad (pbuh) clothes before he went to pray? What was he doing for that to be all over his clothes.

Nothing in the Quran or authentic hadith narrations mentions “thighing” as far as I can find, but it is not forbidden. It is for a man to enjoy sexual intimacy with a woman without sexual intercourse by placing his sex organ between her thighs.

Regarding your other question, during that time it was common for people to keep their clothes mostly on during sexual intercourse, which meant that sometimes semen could get on clothes. The hadiths I have seen in Sahih al-Bukhari do not say that it was “all over” his clothes, just that that there was one spot that had to be washed.