Kim Kardashian -- Ray J is Back ... And He's Moving Next Door!

Ray J is like a bad habit Kim Kardashian just can't kick, because he's just made an offer to buy a house on her street!

Kim's former sex tape partner just wrote a $2.7 million offer to buy a Hidden Hills mansion 8 doors down from Kim and Kanye.

Ray and his business manager, David Weintraub, perused the grounds Friday afternoon and then wrote the offer. BTW, it's pretty baller ... there's even 3 horse stalls.

As for why he wants to live so close to Kim, Ray says it's already his hood. He lived in the vicinity longer than Kim so if anything she's the carpetbagger.

How much would you pay to watch Ray J knock at Kim's door for a cup of sugar and Kanye answers.