Said about a sexually appealing woman, with whom you would be very eager to have sex.
To explain the metaphor: you may be a little too vigorous, and push your penis all the way through her, hence, knocking the back out of her... Obviously not physically possible, but a good, although rather crude, metaphor
Guy A: Phwoar, Check her out, what a stunner!
Guy B: God yeah, I'd knock the back out of that!
62π 13π
Pressing the tip of one's erect penis against a woman's anus in the hope that she'll agree to anal sex. This technique is futile 99.753% of the time, but persists due to the collective male delusion that women secretly love to be invaded in this way.
Boyfriend: (knocking on the back door)
Girlfriend: How many times do I have to tell you??? Get that thing away from there!!!
108π 19π
When someone with a hard on grinds it against your ass while dancing, cuddling, spooning, or just standing behind you.
Tanya loved spooning but hated when her boyfriend used it as an excuse to go knocking at the back door all night.
βThat guy at the bar was cute but he was knocking at the back door all night on the dance floor and thatβs why I didnβt go home with him. Why bring someone home if you know heβs just packing half a roll of Life Savers in his pants?β
29π 7π
When a man feigns an attempt at anal penetration in order to startle his partner.
Woman: I told you I don't do that!
Man: Don't worry, I'm just knocking on the back door.
26π 7π
During anal sex, the person that is doing the penetrating and thrusting is the one that is doing the "knocking," and the anal opening is, obviously, referred to as the "back door."
When Eric and Amy are in bed, he's always knocking at the back door.
42π 40π
n. when a man attempts anal sex without requesting verbal permission. Often involves either precursory acts such as foreplay (rimming, anal fingering) or preceding acts (spreading of ass checks, tapping head of penis on anus, pushing the tip of the penis onto the orifice without full insertion) to signal one's attempt at anal intercourse.
After doing it doggystyle with Jackie, I started knocking on the back door. She didn't object so I totally stuck it in her butt until she screamed.
Richard Johnson kept knocking on the backdoor last night in bed, but I told him to stop since I barely know him.
7π 6π
Polite euphemism for anal sex, just crying out to be written into an updated Carry On film based around DIY enthusiasts.
Jack Douglas : "I'll be finished as soon as I've knocked her back door in and put me extension up"
Sid James : "Hwar har har!"
19π 23π