Threesome with my wife and her sister

After my sister in law, Amanda, and I received a Go from my wife Linda to have sexual fun together, Amanda stays now and then at our home to spend the night with me while my wife has an evening or night shift. We discover more and more what we like and do not like. Sometimes we just kiss or we have soft sex, but sometimes it is fucking each other wild. We also started to experience different positions and we are searching our sexual limits.

This evening Linda is working an evening shift. She will be home around midnight. Amanda stays the night at our house, because both sisters will shop tomorrow. Amanda and I are watching television, but we got bored.

-Maybe we should have some fun together?- , Amanda says.
-It will take a while before Linda arrives home and I would not mind some good sex- , she says with a smile.

I do not hesitate one moment, because I am always in for sex. So, we go upstairs to prepare ourselves by having a hot shower. Both being naked and starting to get horny, results quickly in touching each other and kissing each other bodies. Amanda is standing with her back against the wall and I kneel down to lick and suck her lovely pussy.

-Wait- , she says.
I have to go to the toilet for a pee.

I look up to her. I really feel horny and I cannot resist to ask her to pee right here in the bathroom:
-Please pee in my face and thereafter on by body- , I say.

Amanda is surprised. She does not know what to say for a moment.
-Has Linda ever peed on you?- , she asks.

-No. In fact she has not- , I reply.
-We never got into a situation like we are now-, I say.
-Just try it.