Family friends, with benefits. (Futa/Futa x F/F, multiple characters, incest, ageplay)

Got this idea after seeing this NSFW RWBY piece: 

The basic idea is that I'd be playing two single Futa mom's while my partner plays the two female daughters (If MILF's aren't your thing i'm not against being two much older sisters instead of moms). Back in college MC's used to be friends with benefits, afterwards they went and started families of their own, each having a daughter, YC's. As time went on YC's met in high school and became quick friends and started wanting to hang out, which lead to MC's re-meeting. So naturally, they start fucking each other's daughters to relive the good old times, trading their girls back and forth, fucking them both right in front of one another while catching up and sharing the latest gossip. 

Some key things:

• I want the tone to be pretty light and sex-casual. Like the gif I linked, the girls are letting themselves get fucked and are even feeling good from it. They're just embarrassed about the fact it's their best friends mom fucking them and said bestie is getting fucked by their mom right next to them.
• I didn't mention it before, but incest would've already been part of the girls lives. Their moms would have been fucking them for at least a year before they all met up for the first time. How the girls feel about said sex is up for debate, they could've enjoyed it, or they could've thought it was embarrassing, etc.
• While I do like the 2 on 2 core of the RP, not all four characters need to be present at all times of course. We can switch to 1 on 1 or 2 on 1 scenes as we please for whatever scene we want to play out.
• In terms of ages, i'm wanting MC's to be around 28-mid 30's, for YC's I'm looking for around 15-18 since they're still somewhere in high school.

Anything more specific or that I didn't mention are up for debate.