Ah man basically he does this super secret handshake thing which gets her immediately wet. Combine that with his trademark "scrambler" technique which he developed with Bobby Rio, and she starts gushing from her clunge. You just see it dribbling down her legs and pooling as you realise that it worked.

Try it, let me know if it worked for you. My hand-to-eye coordination is too first person approacher-esque for it to work.