I can't remember... did prince Jedi sleep with someone else?

No. Nicol's sister tried to get him to sleep with her so she could pass off her lovers baby as his, but he has a strong resistance to poisons and refused her.

Normally I'd think he'd have had experience before Nicol because this setting usually means sex is a coming of age thing (and he's a lot older than Nicol). But he said he wasn't desperate to become a man and his reputation was as someone who didn't care for women. So he doesn't seem to have any experience other than Nicol.