Board Thread:General Discussion/@comment-25614818-20150529185748/@comment-995426-20190425162639

Pretty much just Leatherhead that I could recall, and it could have simply been a romantic love as with the Italian Michelangelo. Not that they would necessarily hint too much more in a TV-Y7 show either way, though.

I liked to headcanon that Mikey and LH were physically the same age when they first met, but that LH was probably born on Earth less than three years before then, having aged faster in Dimension X before escaping the first time. But Mikey loves LH just as much whether he's 17 or 70.

The closest other example I can think of off-hand is Michelangelo (IDW), who appears to have the same kind of ambiguously openly pan-romantic personality (blurring the boundary between platonic friendship and romance), but in that continuity he wasn't closest to Leatherhead, but was actually closest to Slash (IDW).