the sims 3 unexpected weight gain, but max sims?

Ok, so on the sims 3, my male sim was making mac and cheese and cancelled the action to ''Investigate Mysterious Anomaly''. He went outside and started to stare up in the sky. A spaceship came down and abducted him! He was gone for a few hours and came back with a -10 Moodlet for 10 hours. After the 10 hours, it said ''Unexpected Weight Gain''. I immediately thought ALIEN PREGNANCY! But he has max 10 sims in his household. 6 pets 4 sims. He just adopted a toddler. Can I keep the alien baby. If not, can I send the  ''Adopted Toddler'' back to social services? I really don't want to starve them because: 1. I have another baby (Who my female sim just gave birth to) that I don't want to lose. 2. It's just plain cruel ☹️                                                                Could anyone help me, it would be really appreciated. I searched all the web and couldn't find the answer to it! 😢