Petroleum jelly?

does petroleum jelly break down the rubber of a condum?

yes. Only use water-based lubricants on LATEX condoms. The oils in normal lubricants break down the latex. You can get many types of water based lube in the pharmacy section of your local wal-mart or shoppers drug mart (if you have any near you) or any pharmacy, located near the condoms. less than $10 for a good one usually.

Yes, it has oils in it. Likewise lotions are not safe - they also break down the effectiveness of condoms. You want waterbased lubricants - available at almost any drugstore or large retailer.