4.5 months & standing up.

My little boy just wants to stretch his legs constantly & stand up. I feel like he's too young, I know at this age they are just discovering new things but I don't want him to hurt himself & I see my husband constantly let's him put all his weight on his little legs, I'm a bit more reluctant. What's anyone else's thoughts? Am I being too strict & should just let him stand as much as possible? Thanks