TGP stands for thumbnail gallery post and it means a site where you can see lots of hot pictures. Typically the sites have a thumbnail preview for each gallery so you know exactly what you're seeing when you visit. TGP porn sites are all about high quality picture galleries for the user. You get to experience these picture galleries as you see fit and you can explore hundreds of different sites. It's customary to find the ones that you like best and bookmark them to come back daily to see if they've put up something fresh and delicious to turn you on again.