To give someone who likes you just enough hope to keep them coming without the relationship actually going anywhere or advancing, and it usually keeps the victim in emotionalconfusion and pain.
Friend: Megan is taking days to respond to my texts, but she also seems to like me; things aren't adding up bro.
Me: I think she is peekabooing you.
ex1:"yo bro Ashley was giving me head this weekend and i was like im gunna cum... so i pulled her head up then i peekachu'd snot and cum all over her face... it was great"
ex2:"It was so gross! I was giving Adam head over the weekend and he Peekachu'd ALL over me ! he pulled my head up and was like PEEKA ...CHUUUUUUUUUUU; i couldnt get all the boogers off of me"