Getting it in

1) Having a meal, getting a good meal in.

2) Sexual intercourse, putting a phallus into an orifice.
Similar but distinct "getting it", which is an adverb.

Im getting it in at Mac Donalds.

get with

The act of intimately engaging with someone who isn't your partner.

Guy: Hey Larry, did you get with Sheena last saturday?
Guy: Yes

get with

to kiss wit sum tounge!

last night bob got with tina in the back room

get on

Australian slang for buying drugs.

"Let's go out clubbing already!"

"Nah I gotta wait to get on first"

get

Puerto Rican slang for a small house party

It is short for the english word get-together

Person 1: What are you doing this weekend?
Person 2: I’m going to Juan’s get on Saturday.

get

to grab the genitalia of another man

Should I get Isaac?

on the get

to scheme or get over on someone or to try and hustle someone

I notice you didn't pay for dinner you on the get. Dang yo only give me 2 instead of 3 hes on the get