Should people in love break-up?

Hello! Be and my boyfriend have been together since 7th grade. My mom has told me since we started dating that we can't stay together forever we have to date other people. Neither one of us want to do that we are happily in love and rarely have a fight (its been almost 3 and 1/2 months since we had a fight)! But my mom doesn't agree. He is the only person I have ever dated... So I came to y'all for help!! Thank you in advance <3!

Updates
10 mo
Also extra info: I am the only child and my Mom's first marriage failed
Should people in love break-up?
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