the real definition of this word is the act of double penetration, or one who performs this act.
Let's buy some condoms & visit Lu Lu she's a doppelbanger
When you pick up twins at the local pub and doppelbang them.
My cousin became a doppelbanger when met the Doublemint Twins during his college days and swears that he doppelbanged them.
Someone who has sex the same way as a previous sexual partner.
"Dude I hooked up with Jess last night and it was like I was banging my ex. They were like doppelbangers or something."