This may have already been asked, however, that being said, does being a pillow friend refer to the fact that the two people are sexual active with each other? And has this only be mentioned regarding Aes Sedai? Any men ever pillow friends?

RJ is pretty ambiguous about sex issues but it looks like pillow friends is the same as fu__ buddies. In the past they have only been women and not just aes sedai, there was a noble woman and a sea folk official who were pillow friends. Maybe we will see male pilow friends, though i doubt it

Pillow friends are close friends who have a sexual relationship, yes. It includes both women who are just friends, and women we would name lesbians. For instance Galina is a lesbian, but Moiraine and Siuan were just friends engaging in sexual activity together, their prominent sexual attraction being for men. It is referred to as other things elsewhere--for instance in Seanchan its called Heart Friends. Whilst we have seen this only amongst women, there are references to men--Moiraine speaks of a male clerk being dismissed for 'innapropriate glances at Accepted' despite the fact that the man had no interest in women at all.

Seems like the Pillow Friends discussion comes up a lot...maybe we should sticky it...  :P