To fool around with a member of the opposite sex in the most
awkward, unruly places. Usually creates
awkward situations in the work place and/or at friendly outings. The term is derived from Diddler, which is commonly refereed to as a child molester. Think of the same situation, but with a person of equal age. The individual knows it's wrong, the public knows it's wrong, yet the person still continues.
Does not consist of sex, but rather
small amounts of human bodily contact, usually not surpassing second base, for lack of better terms.
Dude, i cannot believe you were diddilin with that
chick in your room last
night.
You diddilin fuck.
I was diddilin with that girl all
night, but realized i had work in an hour, so she had to go back to her room.