Don't let your thoughts go very far if you see Arab men greeting each other by nose-rubbing or cheek-kissing or hand-holding as these are very usual customs between close friends in the Arab world.
In the Arab world, as we all know, men are separated from women and usually men spend a lot of time together --so emotions and feelings are conveyed to the same sex.
Rubbing noses is a tribal custom and way of greeting that represents the values of respect, pride and
Bedounism mostly practiced by Arabs in the Gulf region. The nose has a valuable symbol for the Arabs because it is in the center of the face -- it is the place where they greet someone with respect (or hit someone when they mean disrespect). Arab men inherited this tradition as a way of greeting generations from the past.
Holding hands is the warmest expression of affection between Arab men and not only a sign of friendship but of solidarity and kinship. In fact, if an Arab man does not touch the other Arab man, it can be interpreted as he is keeping his distance from him and he despises him.
Kissing cheeks, in the Arab world, considered normal and common amongst male friends and does not linked to homosexuality. It is meant to reflect amity, devotion and most important, equality in status.
Therefore the above are gestures of friendship and respect among Arab men and without any sexual connotation or meaning. Also please note that nose-rubbing, cheek-kissing and hand-holding between men and women are usually considered inappropriate in the Arab world (unless with the same family e.g. brothers and sisters).