Jen, you're up! With the help of pal Jimmy Kimmel, Justin Theroux completed the ALS Ice Bucket Challenge on Saturday, Aug. 23. But what was even better than the Leftovers actor getting wet was who he nominated -- fiancee Jennifer Aniston!

The 43-year-old hunk wore a tight navy T-shirt and jeans to accept his dare. His unidentified friend drenched him with water from behind and he appeared to have several others looking on. Kimmel posted the video via Instagram.

"I would like to challenge members of the Lab[yrinth] Theater Company in New York," he said. "...David Lynch and because she's not here to see me do this -- Miss Jennifer Aniston." (The couple recently reached the two-year mark since Theroux proposed on his 41st birthday back in August 2012.)

The HBO star was so cold after getting splashed that he said he couldn't even talk.

Watch the video now!