Public displays of affection between any couple isn't encouraged in Gulf cultures, though I don't think anyone will give a hoot about same-sex hand-holding on an aeroplane. Off the plane modesty and restraint are the rules for all behaviour, so ostentatious displays will grate: a case of "get a room".

Employing gentle terms of affection is fine: various forms of "habibi" crop up quite naturally between friends.