You don't even know if the toy was used. And too hip is right, it would be used just recently. And why would your lip be bothering you as your lips weren't involved, were they? Were you kissing it? There is a slight risk of herpes transmission from a sex toy but from all I've read, this is when it is used during the act with an actual person and very fluid filled or covered.
Have you had any symptoms after the use?