Now thats an interesting idea.
If I'm not mistaken wasn't there also some conjecture that Elita-1 and Optimus Prime could mate with each other (aside from
The Hunt for Alpha Trion which seems to support that).
Oh, and he wanted evidence of "Robot babies"...while not
Transformers per say Kranix and the population of Lython did transform.
Oh and of course there is Rattrap's infamous throw away line "scouting the enemy huh? find any new [sexual] positions" (or at least that's pretty clearly what he was implying).
You could probably throw the whole Wheelie thing out the door since it's been known Transformers "adopt" sons (Cryotech makes reference to this in regards to Megatron), although it's not as easy to throw Deathsaurus having a wife and kids out except to say that the Japanese Transformers are really f***ing weird, and if we're going to consider their opinions on things we might as well just shoot ourselves in the heads right now -- save us a lot of trouble.
Also, Wreck-Gar
clearly has a wife in both the G1 toon and comic (the comic and cartoon actually are just the same story, the comic being an out of continuity issue). It's probably reasonable to surmise that Wreck-Gar is simply mimicking a TV marriage, he even names his wife "Nancy", a very human name.
Jhaxius created Arcee in the IDW continuity after observing organics and wanting to know how females would influence the "male" Transformer population. He also pretty much says she is capable of having sex. Moreover Arcee is Rattrap's [great] Aunt, and she's a ****e since it's clear she slept with Springer, Rodimus, Bumblebee and Chromedome. Then there's the whole Daniel Witwicky relationship - and they
did seem to have developed some pretty intense feelings for each other in the BotCon exclusive comic. Thankfully Daniel Witwicky died in it so we didn't have to overtly deal with the creepiness of Acree and Daniel having a "relationship" - yeah, I just threw up in my mouth.