The Biology of Music - I fucked my trans substitute teacher

"Now what will we do about this?", she asks in a matter of fact way. "Maybe you should take it out so I can have a look at what we're dealing with"
I open my fly, and angle my penis out with my hand. It bends, and then flicks out, looking up towards the ceiling.
"Oh my", she reacts. "I'm glad we released that when we did. I'm not sure it could stay in there much longer".
I smile at her and she moves towards it. She pushes her hand onto my chest and moves her way down towards my penis into a crouched position in front of me. She kisses the tip of my penis and pulls the foreskin back. I have never had sex before and I'm afraid I'm going to cum too soon.
"I haven't ever done anything with a girl before", I admit to her so she understands if I cum in the next 4 seconds.
"how about with a boy?", she asks.
"No way. I'm not gay!", I rebuke immediately.
"Oh not even a little curious?
I am taken aback by the question. Admittedly I have masturbated while thinking about some of the boys in my class before, but only the ones that look sort of feminine. An occupational hazard of going to an all boys school I thought.
"No way", I reply, fearful that she is testing me to make sure I am all man.
"Oh that's a shame. I thought you would be cool with me"
"I don't understand. I am just super horny and not very experienced. I'm afraid I will cum too soon"
"Well you can cum after I cum then. You're not the only one with an erection you know..."
I am again very confused by what she has just said, but I don't know all the sex things, so I just go along with it. It does stick in my head though. What does she mean? Does she have an erection? What does that mean? Is she trans?
She stands up and kisses me. She puts her hand into my shirt and rubs my chest. She puts her tongue into my mouth and starts massaging my tongue with it. I have never been kissed like this before. She is clearly a very sensual woman, disinhibited. I open my mouth and wrap my tongue around hers and we kiss deeply.
She kisses me again and then turns and walks to the piano. She sits on the closed piano and ushers me over. I make my way towards her.