I get ya...here is the fee just in case you decide to go FTT.

What also works for me is to be told by her during session that it is going to happen, at which time I need to hand her the money. In my fantasy she would count it slowly in front of me.

In all likelihood we would both know that it is going to happen, it is all about ceremony. I actually wouldn't mind if she told me that she was ambivalent about using my mouth but wanted the extra cash. So hand it over and open wide.

I actually did have a session once with two mistresses and one was telling the other that she might take a shit in my mouth because there was a pair of shoes that she wanted to buy. But she might have been playing with me. It didn't happenn.

I guess YMMV.