You kissed Marty, the feminine boy your girlfriend has become.
At first, you find weird kissing another boy.. you are straight after all! But this is your girlfriend.. and her real name is... is..??
This is very strange, you can't remember her real name!! You suddenly stop kissing her.
"What..?" She asked, a little surprised.
"Honey.. this is weird. I can't remember your true name, I mean your 'girl' name."
"What are you talking about?? I'm Marty!"
"Yes, that room changed into Marty, but now I can't remember you as a girl."
"A girl?? Yes, I ever wished to be a girl and I try to be one.. - she/he responded - ..but unluckily I'm always a guy. But for you, I am the sweetest girl, is'nt?"
And then Marty started kissing you again. Marty, of course! Her.. no, HIS real name is Marty. Why you remembered him as a girl??
Slowly, every memory of your previous girlfriend faded, and was replaced by a similar remember about Marty.
Your first date with him. Your first kiss. Yes, your only girlfriend is Marty, and you love him crazily. And kissing him very deep, the last thought about your former girlfriend was gone. Forever.