Moderately bad.

You decide to hook some people up with the transformation fluid and see where it goes from there. You choose to walk up to the tranny who lost her date and sit in her lap.

"Oooh, you got a big one," you tell her as you feel it grow between your legs. Without even waiting for the response you know won't come, you reach under her skirt and find it easy to slide the front of the tiny thong aside since it was only covering the head anyways. Your own skirt is already allowing access since you stradled her lap and so your pussy gobbles up the tanny's cock. It must be 8 inches but very very thick. You lift your shirt and bury her face in your cleavage. You start riding hard, enjoying your female parts fully. You squeal loudly as you begin the first of many orgasms. You are surprised how different it is from a cock orgasm. Best thing is you don't get horribly tired after the first one and keep going. You hear a muffled sound from your chest and feel heat spread in your pussy. You stop and feel the pulsing cock. So this is what it's like to get cummed in. Not bad, as it keeps your own orgasm going. You don't know why girls always made you use a condom before. They were missing out.

Then someone taps you on the shoulder. You forgot you were in a public place.