
poppen
to fuck
A colloquial expression, often perceived as vulgar, for having sexual intercourse.
Die beiden haben sich auf der Party kennengelernt und später miteinander gepoppt.
The two met at the party and later fucked.
to fuck / pop
Loading your saved state.

to fuck
A colloquial expression, often perceived as vulgar, for having sexual intercourse.
Die beiden haben sich auf der Party kennengelernt und später miteinander gepoppt.
The two met at the party and later fucked.

to pop
To make a short, popping sound, similar to the sound of a cork popping out.
Als er die Sektflasche öffnete, poppte der Korken laut.
When he opened the bottle of sparkling wine, the cork popped loudly.

to pop up
A term borrowed from English for the sudden appearance of something, especially windows or messages on a computer screen.
Ständig poppen neue Werbefenster auf meinem Bildschirm auf.
New advertising windows keep popping up on my screen.
The three meanings are clearly separated by context. The vulgar usage refers to people, the sound refers to objects (such as bottles), and the appearance refers to computer elements.
Auf dem Bildschirm poppte plötzlich eine Warnung auf.
A warning suddenly popped up on the screen.
In the meaning 'Geschlechtsverkehr haben' (to have sexual intercourse), 'poppen' (to fuck) is very colloquial and is often perceived as vulgar or at least very casual. It should absolutely be avoided in formal situations.
Im Film reden die Jugendlichen sehr direkt übers Poppen.
In the film, the teenagers talk very directly about fucking.
In the meaning 'knallen' (to pop/bang), 'poppen' (to pop) is an onomatopoeic word. It imitates the short, bright sound it describes, most commonly when opening a bottle of sparkling wine.
Wir hörten es in der Küche laut poppen und wussten, der Sekt ist offen.
We heard a loud pop in the kitchen and knew the sparkling wine was open.
In a computer context, the word is very often used as the separable verb 'aufpoppen' (to pop up). It then means that something suddenly appears on the screen.
Immer wenn ich diese Webseite besuche, poppt ein Werbefenster auf.
Whenever I visit this website, an advertising window pops up.
to fuck
Vögeln and poppen are colloquial and often vulgar expressions for sexual intercourse. In casual language, poppen usually sounds somewhat more playful or milder. Vögeln usually sounds more explicitly vulgar and can come across as harsher; neither word is appropriate in polite situations.

Sie sagte scherzhaft, dass die beiden miteinander gepoppt hätten.
She jokingly said that the two of them had fucked.
Er sagte grob, dass die beiden miteinander gevögelt hätten.
He said crudely that the two of them had fucked.