This is what I love about Sims 3 too. The subtlety of the expressions and the low-key reactions that make scenes like this possible.
Taking a bite out of her fish, she commented, "This isn't bad fish, is it? I like the taste."
"Yeah, with red herring, you gotta watch the bones..." Animal replied picking a bone out from between his teeth, "Maybe if the bones sit long enough they'll become brittle enough to become fertilizer for any plants..."
https://2.bp.blogspot.com/-5zEV_SNJU-0/XuVfCDVa7oI/AAAAAAAAgto/D3XMt3urzTQmxicqVgXioM3th_pSzqmNQCLcBGAsYHQ/s1600/Screenshot-40.jpg
Butch looked soberly at him, the hard-edged competent naval officer was gone and the look of a scared mid-twenties young woman replaced her, "You think we're going to be here for a long time?"
https://1.bp.blogspot.com/-_6yxtwOIE_A/XuVgH2sITqI/AAAAAAAAgt0/XDOnO62Z1mkqwScInkpJ1mezW-w7rh3RACLcBGAsYHQ/s1600/Screenshot-47.jpg
Animal didn't want to frighten her, but he also had to prepare her mentally for that eventuality. "I hope not..." he said finally, "But the possibility is there that we may not be found."
https://3.bp.blogspot.com/-wbo7kFUKEVw/XuVg146fd4I/AAAAAAAAgt8/rLdCrqeLy9Uk-Wz3KL_pvtsaEQqG_7jtwCLcBGAsYHQ/s1600/Screenshot-48.jpg
"...and what happens in that eventuality?"
https://3.bp.blogspot.com/-zFlWoMGBr7Q/XuVhVHo8H-I/AAAAAAAAguE/xJdm-jZ2YRASD7L6iO_VsE6KQEh3TgEEwCLcBGAsYHQ/s1600/Screenshot-55.jpg
Their expressions make this exchange take it to another level.
Unlike a certain iteration of the Sims game, you're not fighting the over-exaggerated expressions just to be able to tell a story...and I'm not even using Moviemakercheatsenabled; this all came from watching the sim and taking a screenshot when their expression matched my story or vice versa tailoring my story to match the expression. Thank goodness for low-key expressions.