I've been having this issue for a couple years now. No matter how self-lubricated I am, or how much lube I use, I have discomfort during vaginal sex with toys. It feels like a not-quite burning sensation, kind of like when you get a brush burn but it happens slowly (Sorry, it's hard to describe in terms that don't make it sound more horrific than it actually is), or when you have really dry sex, which I guess is also what's happening, because I also stop self-lubricating when I feel the discomfort. My partner only used silicone dicks (from Babeland, so I don't think there's any hidden material that we weren't told about), and we switched from latex to nonlatex condoms to see if that made a difference, but it only helped a little. We're not on speaking terms anymore though, so I can't ask for a link or anything to the product page. I do not think this is a matter of size or tearing, as I've not had this problem with thicker penises. I had been tested for STIs a few times while having this problem, and came up negative.