A slang phrase for performing fallacio (oral sex) in a public place.
Brian: What is that tramp doing?
Keith: Giving street head
Brian: That is rank.
Jess: Where did Jasmin go on Boxing Day?
Ellie: I'm not too sure I think she went out.
Jasmin: Sorry guys, went to give some street head didn't I?
Jess & Ellie: That's our boii!