Adult backlinks to avoid

Hey guys, I'm running an adult (porn) website. The thing is it's the first time for me running a site on this niche, I mean adult niche.

I'm thinking about buying backlinks (I've done this before) but I'm not sure where and what to buy for this web.

So I want to know, which are the kind of adult backlinks I should definitely avoid? I don't want to f*ck up this site.

Thanks in advance!

I am in a niche that is adult (sex toys), but not porn. I think the same rule apply to pron as other niches. Just stick with getting backlinks from bornsites that have clean profiles, don't have backlinks to whole bunch of unrelated niches (ie pharma). I don't know why some porn sites do this, when tehre are a ALOT of porn websites where you can link from.