Sure, I'm gonna lose but ok

As a courtesy you willed the Jenga tower to be assembled and your 5-6 inch tall body looked up at the two foot tall Jenga tower "Ok... I'll remove the blocks myself but either you let me poof the pieces up there or you'll have to do it for me. Unless you just want me to immediately lose."

Claire chuckled "Sure, I'll do that for you. I do want to actually play even if it'll be lopsided. How about you go first?"

Turns out you weren't antman. Your strength was weaker so unless the block you were trying to pull out was very loose it'd be impossible for you to muscle it out much like it'd be tough to move a wooden log anywhere while it was weighed down by other wooden logs. Still there was one near the base that you managed to pry out without completely shaking the whole tower, and then Claire did you a favor of picking the brick up and putting it on top of the tower. And just seeing the tower sway a little you just made yourself invulnerable. Claire poked the tower bricks a little bit before pushing out a pretty easy brick from lower on the tower and put it back on top. Another round and you were sweating... In the abstract playing Jenga while small sounded maybe a little fun, but actually being next to a tower that could fall on top of you was nerve wracking. You managed to get another brick out, but you were pretty sure you were doomed at the next round. You saw an angle and asked/yelled "Hey Claire!" to get her attention and it worked.

"What?" Claire asked as her whole upper half turned and half a second later her breasts scooched themselves across the table and slammed into the tower... and on one hand your plan worked, but on the other hand you had misjudged the wall of flesh and wooden bricks falling at you at relatively high speeds. Claire went through annoyance at being tricked, relief at her breasts shrinking to their regular size as she lost the game, and then finally concern as she fully noticed that her once large breasts had batted you off the table. "Where are you? Are you ok?!?!"

Somewhere near a chair you muttered "Yeah... I gave myself some invulnerability just in case the tower fell on me." Claire was able to find you thanks to your words as you picked yourself up "And I do believe that I won so I get to make a change."

"What going to puff up my boobs again?" Claire asked you smirked as a warp of reality later we were now both standing on the game table but Claire was looking up at me. "Huh?" Claire said confused at the change in perspective and then said "You shrunk me to an-" she noted the gap in their heights "Hey you shrunk me a lot further! I'm not this short!"

"What? Your just an inch shorter than me like normal." you said rationally

"Yeah, but that means I'm now 20% smaller than you instead of being around your height!" Claire said pouting

"Hey, I won. I get to choose how big you are. Besides now we can play a game at a similar small size," You said "and I believe since you picked Jenga I'm allowed to pick..."