It's your birthday and your girlfriend has agreed to let me give you a handjob. We have a bit of a crush on each other. She's watching to make sure we don't do any more... but she gets so turned on, she can't help but touch herself over her clothes.
I'm going to talk dirty to you... remind you how big and thick your dick is. I wish your gf would let us do more... and I can tell she likes to watch.
Finally, you cum on my chest and tease your girlfriend knowing she will want to watch more. Maybe she will let us during your birthday!