Othodox jewish people dont like to be touched by a woman because it is against there custom to come into contact with a woman whilst she is on her period. I have heard of incidences of pax asking a crew member if she is on her period! Though i think most have the decency to be more discreet. At check in they will often ask to be seated next to a woman, Though this sometimes doesnt happen and i have had to sort this out on board before.
They also need time and space to pray on the aircraft and must not be touched by anyone whilst doing so or they have to start again. Dont quote me on that last comment im not 100% if thats true but the woman rule is definately true
Sorry dont know how to edit but i meant to say in that first paragraph that they will ask at checkin NOT to be seated by a woman.