I Bet He's Thinking About Other Women

Currently no, not for users like you and me. One imperfect indicator of how long ago a stream was created is finding the oldest image on that stream.

How 'bout them aliens :) imgflip.com/i/l6yni

maybe a feature that could come along in the future.

First images on Imgflip were uploaded June 2011 into what is now the fun stream.

Oldest gif on Imgflip (fun stream) was from September 2011: imgflip.com/gif/530

User created streams came a little later, spring of 2015 I think.

Oh okay. But what is the first user stream?

Not 100% sure, it's entirely possible the first user created stream was deleted lym95.jpg (click to show)

Like, user-made stream

Some early user created streams still exist and are listed in ekult's Stream Compendium here:
imgflip.com/i/l5jxq

Cool, that's a long list.

It would be nice to have it added.