I've only had a couple of visits where the gentleman tipped afterwords. Usually, the man has done some research and knows what he's about to encounter. When a tip is received, it's usually included in my initial gift. Once or twice I've received a modest tip, thanked him very sweetly, and then, when I was putting away my gift I realized a tip had already been included. The few who've tipped afterwords have discretely, but noticeably placed my surprise token on the nightstand or table on their exit.
A friendly tip though, if you decide to tip afterwords for whatever reason, excellent encounter, just your policy.. Try to always go to the restroom and separate whatever you wish to surprise your sweetheart with. Instead of subjecting either of us to the sort of uncomfortable and awkward moment of searching for, choosing, and hand delivering. Those kinds of transactions just give me an icky feeling for various reasons. We should all practice the art of subtleties. Besides, who doesn't like surprises? I for one, am a big fan. It kinda diminishes the POP of excitement from getting my reward for excellence if you do it right in front of me. Life lesson. <3