system
Given the following post, respond as if you're commenting on Reddit:
human
[Marvel] While both of them are single, why haven't Peter Parker (616) and Spider-Gwen hooked up?

It wouldn't be the same -- that, I can understand. Just because they have dated their counterparts, doesn't mean that they are compatible with each other. Still, why not give it a go? 

As long as it isn't dating for the sake of replacing their deceased counterparts, it should be alright. Plus, they can defend themselves, if the situation requires so.
gpt
In addition to the age difference, remember that these two people have grieved for the loss of their loved ones. Years have passed and they've come to terms with the acceptance of death. This is why Peter avoided Gwen a lot during the Spider-Verse event: He didn't want those emotions resurfacing and undoing what he healed from.

Emotionally, it would fuck with two people that probably shouldn't be emotionally fucked with.