GUYS & GIRLS: What does it mean when a guy friend jokes about marrying you?

I know this a stupid question & nothing to take too seriously, but I am so confused! I've liked this guy for ages now & he liked me too, but nothing really happened between us, minus a few casual dates & some flirting.

The problem is that for a while now I've been (& some of our friends) suspecting whether he had a thing for my best friend (also his really good friend), who has a serious boyfriend. I know he talks to her a lot about his personal issues as he's had a tough life & has been going through a lot lately. He confides in her & hangs out with her (as part of a group including me), texts her & is always joking around with her. He also paid her a compliment once, yet he's never given me a compliment in all the time we've known each other. I get plenty male attention & guys regularly compliment me, yet he never says a word, which once again makes me think that he's not attracted to me. He jokes around with me too & playfully argues with me all the time. In fact, we always banter & joke with each other, playfully fighting/arguing. He's a very charismatic, witty guy & everyone loves him. He's also very friendly & has a big personality. I'm getting worried that he's into my best friend more & more. Sometimes he'll say to her "you know I love you" & laugh. Today he said to her while we were all chatting that if they both single by 30, they should get married. He then asked me if I would marry him. We all joked around with each other. He then said he'd rather marry me first & her afterward if things don't work out between us. I know this is silly, but I;m just wondering what it means? He also calls her names like "my home slice, gangster" which would imply he sees her as a friend, but I'm not sure :( He then said to her they should have coffee on the weekend & then he joked to me that I wasn't invited. He later asked if he could come with us on our girls night out?

In a nutshell, I've been getting mixed signals from him for ages. Even today he asked me why I hate him (once again jokingly). We love to be sarcastic to each other & screw around. He later said in the same conversation that he wanted to take me out for pizza, but just us? I know none of this sounds like much, but recently when I had my birthday, he invited me for a 3-course lunch at a very fancy restaurant & it was just the two of us. He still said to my best friend that she couldn't come! He was a complete gentleman & we had an amazing time together. Surely he wouldn't have gone to so much trouble if he just saw me as a friend?

Please help! There's so much more to say & the things he regularly does confuse me! Also, when my bro (one of his best friends) said told him how much I liked him, he didn't believe my bro. What should I do?
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PS: He also said to my best friend when we were leaving "say you love me" & we were all laughing. He then said to us all (there was another girl with us, also his friend) "love you long time" although he said to me, "I'm not saying that to you because you hate me & you always sass me & you're sarcastic" he was laughing while saying it.
GUYS & GIRLS: What does it mean when a guy friend jokes about marrying you?
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