If a guy brings up marriage in a relationship, is it something to worry about or dismiss?

my boyfriend kind of brought up " well, we could get married" casually in conversation, then played it off as a vague idea and I was like, oh cool nothing to worry about, he's not serious.

then I told some mutual guy friends about it, and they're like "dude, if a guy brings up marriage in a relationship, ...thats pretty weird." and I told them that he was probably joking and all I got was silence, then one of the guys told me to please not get married at age 18 and whenever I said he's not serious, they just gave each other weird looks.

my boyfriend usually doesn't say things he doesn't mean, should I be concerned?
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+1 y
also, we've been dating for 4 months, and he can't even say "I love you" yet.
If a guy brings up marriage in a relationship, is it something to worry about or dismiss?
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