So on the level of 'is it ok?' I'd say it's OK so long as everyone included in the RP is enjoying it (because that's what matters). Something I've noticed on RPG specifically is that there are a lot of [i]underage[/i] roleplayers or roleplayers that [i]appear[/i] underage that RP smut. But overall the smut community on RPG seems to be pretty dead or is more prevalent on other websites that cater particularly to writing smut (because as much as it pains me I cannot call it erotica when you write a paragraph about 'stick de pepeepee into the vagene', lol). 

I've also noticed that a lot of the ERP on RPG is super low quality comparable to free RP levels of writing (oneliners or single paragraph) which isn't a problem but just doesn't do anything for me. Combine that with low-brow writing styles, word usage and overall not the greatest sense of literacy and you basically have the perfect means to make any literotica writer shake their heads and move to greener pastures. I'm not saying this is bad, since as long as both sides enjoy it, I'm OK with it -- I'm saying it doesn't do anything for me. 

I've also had some bad experiences with partners whether it be unsolicited OOC stuff that I wasn't interested in or just downright weird stuff that wasn't sexual but just made me really uncomfortable. 

This is my reasoning for [i]mostly[/i] passing on the matter of ERP.

But literotica is something else entirely to me, but it's just impossible for me to find partners that write literate erotica and who I can get along with.