Why has my boyfriend joked about marriage, kids and a future?

It all began when we were seeing eachother and he casually asked me how old I wanted to be when I married. We are eachother’s first ‘real’ relationship and he’s a pretty shy guy at first regarding emotions so I was surprised by this.

Another instance involved him randomly saying something like “…As long as we achieve our career goals first”, when we were discussing them. I couldn’t help but wonder what ‘first’ must’ve meant, and whether he was alluding to possible marriage plans for the future. Note I have NEVER brought up the topic of marriage or long term wishes with him, for I have been too shy.

Moreover, I recall him mentioning his good friend becoming engaged, me replying “Ah yeah, that’s cute”, to which he replied “Yes, I know it is”. In front of a good friend of his, he joked that my future company name will need to change to include his surname, instead of mine, while discussing potential business names. This particularly surprised me, seeing it was in front of a mate.

Furthermore, while discussing long term goals again, he joked: “…unless you wanna get married in the next year instead. Lol” I just casually laughed it off, while he said “Don’t laugh- it could happen!” Not sure whether he meant me getting married in another year in general to whomever, (Note I’m 18.5 years old) or me generally marrying him in the future.

Not to mention, he jokingly ‘proposed’ to me a second after he saw a guy do it on TV, and joked to his friend that “My girlfriend would invite my cousin to our wedding”, after his friend joked not to invite her to his wedding when the time comes because of her being supposedly annoying.

Last, but not least, he’s joked that “Our kids would have nice eyebrows” when I complimented his. Also jokingly asked me if I would have 10 kids after seeing it on A Current Affair, asking why not when I said no (most recent).

What could these mean, especially if he’s a shy dude.

P.s. he sometimes uses the word ‘future’ when talking about us.