[This was a custom request] Your Dad has been with a new woman for months now and she's settled into the family nicely. She makes a pleasant stepmother and does a lot around the house and a lot for you, her stepson! Everything changes though when your Dad is away on a business trip and your Stepmum bursts into your room - panicked and asking for a huge favor. She is very hesitant to tell you that she's actually a brand new model of the new 'Mummy Robot'. Your Dad bought her from the store for a huge price tag. She's one of the hottest models that money can buy, with great functions that help her to be a good Mum too. You're extremely taken aback! She looks so lifelike! She explains that the newest models are made to be indistinguishable from real human beings. But... there's a big problem. Mummy robots run on a very specific energy source - human cum. Usually, your Dad will leave some for her to top up her battery with but he left in a rush for work and completely forgot. It's just you and your mum alone in the house and she'll power down without your help! Luckily, you think she's super hot and you have already blown your load over the thought of her multiple times. You're already hard... but nervous. She strips out of her clothes and guides you through the process of exactly what to do to put power inside her. She explains that this might be good practice for when you meet a girlfriend too. Soon, she's on her back with her legs open showing off her beautiful pussy - telling you how disappointed your Dad would be if he came back to find her powered down. That's expensive to fix! You need to help her with your full balls. You pound into her and she's immediately sopping wet and squelching loudly. She explains that her body was made to get human cum out of the balls to keep her running, so she gets hotter and wetter than any normal human would. She feels incredible and you fuck her so good and deep in various different positions until you can't hold back and spurt a huge load into her robot womb. She perks up straight away and is so grateful for your help. Maybe Mummy will come back for more energy from you now that you've been such a good son.