I’m pregnant but not with my boyfriends baby!

I’m 16 && about 2 months ago I lost my virginity, we were having sex still after we broke up because he was the only dude I trusted enough to let him do that to me. So about a month later I started messing w/ another boy. We already knew each other but I had him to stop texting me because I had a boyfriend. && now me and the new boy are dating && we had sex maybe 2 times. Now juss 3 weeks ago I had sex w/ my ex because I wasn’t messing around w/ the new boy yet. && we didn’t have a condom so we were going to go w/ the pull out method. It didnt go as planned. And now I’m pregnant by my ex && his parents want me to keep the baby. I haven’t told the new boy yet or my mom. What should I do && how should I tell both of them?