Tips at paid events; yah or nah?

Looking to stir up the convo on your thoughts about having a tip jar out at an event that has already been paid for by clients.

I have only left a tip jar out when doing big events like for corporate company's but never at a private event such as a birthday party or wedding.

Recently, I was servicing a wedding and was asked several times where my tip jar was or how much for the photo's. Someone at this wedding had told me I should always have a tip jar, hence my debate on the subject. I feel its rude to do so if the main hostess had already paid $xxx amount of dollars for me to service their event.

What do you think is the most professional way to go about the matter of the TIP JAR???