AJ is a nickname for a male. Usually short for first and middle names. AJ's are ladies men and get a lot of girls. They are very flirty guys, but when they get into relationships they become loyal and tend to let their significant other control them or whip them around. VERY good in bed, and also a very good friend.
*AJ passes 20 to friend*
*Friend walks up to girl*
*Friend walks away*
*Friend gives AJ back his 20*
Friend: "You're right she does have pretty eyes"