My slutty milf boss wants to have a foursome with me and her sisters [MF]

A couple months back I (M24) posted about how I fucked and impregnated my (F38) milf boss. Since then she decided that she doesn’t want the kid so got an abortion but is divorcing her husband as she realised her marriage isn’t working. We are not dating but we are having a FWB type relationship and she spends lots of time with me letting me do whatever I want to her (she’s really submissive and begs me to dominate her in any way I want). She’s a complete slut and loves being degraded in any way I can and does whatever I want in the bedroom.
Last night after a hard fucking she mentioned that she would love me to also fuck and claim her two single sisters (F29 & 32). She’s shown me photos of them both and they’re also both really hot and she says they’re just as submissive and slutty as she is. She even begged to have a foursome with me and her sisters.

She’s set up a date next Friday where all 4 of us are going to meet at a bar and hopefully they’ll come back to mine and we can spend the weekend fucking like rabbits

I [M] fuck my boss [F] and get her pregnant

So, I (24 M) have just graduated from university and have been hired at a recruitment company. For context this is a very small company of about 10 people and my boss (38 F) is the owner.

At the interview it was after working hours and just us in the office. It was going very well and I was pretty sure I was going to get the job and what happened next made me sure.
My soon to be boss pushed her notepad away and said “so, that’s all the formal questions over, can I just ask, have you got a girlfriend or anything?” I told her I didn’t and had been single for about 6 months. We chatted for a while about our personal lives until she stood up and pushed my chair back and sat on my lap kissing me hard. Obviously one thing led to another and we had hard and rough sex in the office for about 20 minutes and ended with me cumming inside her.