2. to do something with another person which might be considered, if not by you yourself, then by another person such as a girl/boyfriend, of an intimate nature
3. to mess around or joke around with
2. "yo, baby, trust me, im not fucking with any other girls, i promise you, when you saw me with marie, we were just walking cus i ran into her at a record store, thats all"
3. "you gotta be fucking with me, right, there is no way you went to england for 200 dollars roundtrip"