Didn't see it posted here, so I thought I'd give this little project by MagnusMagneto a signal boost:
http://fav.me/d8maieq
It's a work-in-progress text-based game you play in your browser, where your girlfriend outgrows you in both muscle and height. Every step along the way you can talk to her to see how she feels about various aspects of her body, make comparisons, and also armwrestle her. She'll say different things depending on how much she's grown and also how strong/large she is relative to you (since you yourself can grow or shrink based on how often you workout).
It's up to Version 2.1 right now, so hopefully it'll keep updating.