The context of the following conversation is Robin decorated her room like the ocean, so you could say that Robin slept with the fishes.:
Robin says I love this new color of blue..
The friend responds Yeah, It totally gives me a water kind of feel..
Robin responds It makes me feel like I'm in the ocean..
The friend responds Yes, I guess you can say I sleep with the fish..
Robin responds That is funny and cute..
The friend responds Thank you..