If you must, make sure to check to ingredients. Glycerin and vagina's don't normally go well together. Also, oil can completely ruin condoms so it is completely UNSAFE to use with condoms. I'd recommend using a different type of lube; oil based if you're looking for that texture/thickness.
I heard a couple people do this. Im wondering if it is safe.
It's not really recommended as some women have problems with oil causing over growths of yeast or bacteria. Silicone or water based lube is best for vaginas. Now if the couple is male bodied oil based lubes are fine, as I understand it.
As was mentioned earlier: oil can cause a condom to break down and break. Something to consider.