一いっ発ぱつやる

godan verb (-ru)

have sex; bang someone

Vulgar slang used mainly by men; equivalent to 'do it' or 'get laid'. Often implies a casual or one-night encounter.

• 昨日きのう、彼かの女じょと一いっ発ぱつやった。

  I banged my girlfriend yesterday.

• 飲のみ会かいの後あと、あの子こと一いっ発ぱつやるつもりだ。

  After the drinking party, I plan to have sex with that girl.