While Roleplaying, think of it like being an author of a book, although you’re in this case, writing the story with someone else and building of each other (atleast thats how an «ideal» RP should be) Truth be told though, this dosent happen too often, but you can always do your best, however, if your partner dosent give it their all, then neither should you
In a way, be as detailed as you wish for them to be, but if they dont respond with the same amount, then tell them, invest as much energy as they do or just leave. Last one might not be too popular for some to hear but its just not worth it at times.
On the topic of details though, for it to be erotic you should do your best to take note of what you and your partner like and try to add it into the text/scenario.
An exanple would be that many men on here like getting a «tease» of womens breasts, so say I in my case at times add in something among the lines of
Reaching for the mans plate, I politely excused myself as I leaned between him and his wife, feeling his gaze locked onto my cleavege as I took my time, giving the man just barely enough time to see them and leaving him to wonder how they would feel while I would moan into his ear.
Very porn like and I couldkve probably written that example better, but as I just said, it’s an example
If possible, take your time before the RP to discuss such interests, and of course, should you not share interests, find someone else. Wish you all the best of luck!