Lust Pin is an adult-themed Pintrest service that allows people to share, enjoy and engage with adult content from a user-curated point of view. Basically, this is a community effort to find out the best of the best when it comes to adult entertainment, and you're going to be able to enjoy a lot of amateur snaps, celebrity selfies and hardcore porn clips as soon as you visit the site. Note that Lust Pin is a relatively new service and is still in its beta testing stage: that doesn't mean it's not good, but you can expect to come across a bug or two while using it.
I recommend skipping over the homepage for now, as I don't think the design is finalized and some broken images appeared for me when I was trying to use it. Instead, hover over the 'categories' link in the header and select whatever it is you're keen on. Choices include niches such as Asian, BBW, blowjob, celebrity, ebony and lesbians to name but a few. Each category has a decent number of submissions created by users on the site that you can vote on, repin and enjoy. As far as I can tell, Lust Pin is all about pictures right now, but they may allow GIFs in the not too distant future.
I think that when all things are considered, Lust Pin is a good alternative to some of the other listed Pintrest-type websites that we've featured in this category. It's easy to use, signing up takes less than a minute and the more people that contribute, the better. It might not be as popular as Sex.com or Smutty, but neither was Facebook when MySpace was at its peak.