The inability to focus on one sexual act enough to allow one's partner to ejaculate.
My ex could only blow me for a minute before she tried something else that was much less effective. I never came during a blowjob. She had sexual ADD. And she sucked at sucking.
A description of a person's attitude towards sexual activity that generally involves moving from partner to partner in a short timespan, or cheating, and is used to describe the activity when there is no other explanation.
Tim was in a relationship for two years, but his sexual ADD caused a return to his single status after a midnight rendezvous with Cindy.