1. Saw a cop earlier
2. The little-to-a-shitload of paranoia the marijuana produced
3. It's cold as fuck
4. You have to catch something(like a movie or family dinner) that required you to be high in the first place
5. The whole situation is just sketchy
To 'dip' means to dip out of the place, dip out of the situation, etc.
Pip: Hey Quart, it's roachin' now, let's hurry up.
Quart: Why hurry Pip? I was thinking we could bust out the bong after this blunt.
Pip: Naa, I'm good - high as fuck and I'm kinda gettin paranoid..
Quart: Damn... not again bro, you gotta cut that shit out if you're gonna rip with me.
Pip: Well I wouldn't be as paranoid if we didn't see that cop car a few min ago.
Quart: Yeah I guess, let's just rip and dip.
Same people above are smoking yet again, another schwag beezy in the creek behind Pip's neighborhood.
Pip: Yo Quart, this roach is about to die, should I kill it?
Quart: Yeah I got the piece here too.
Pip: Na man, I was plannin on just rippin' and dippin' tonight, no long sessions - I have a popcorn family party to catch in a few minutes.
Quart: Oh wow you're a pussy Pip. It's fine I guess, I'll jus smoke it at the party I'm going to later tonight.
Sometimes this can be used as a crude way to describe a violent quickie.
Dude #2: "Yeah! Someone got us big time with a severe Rip and Dip!"