When someone is deceiving you into believing that they are something other than what they really are.
A co-worker at my job is snowballing the supervisor into thinking he is doing his share of the work. He actually is a slacker who is not pulling his weight.
1."Wanna..wanna..snowball?" "I..don't know..I'm not really like that." "It's..just to help eachother out you know-I mean..just pretend." "Well...I guess..Oh...that..feels..so..goood...."
The act of a girl swallowing cum from the asshole with a straw and spitting it out in another girl ass full of cum. The act is repeated gradually increasing the amount of cum, thus the name snowballing.