It's not a deal breaker at all. I'd be very happy if my boyfriend told me he wanted to marry me someday. We've talked about stuff like that and it makes me pleased to know that he's thinking about me that way. It'd be a deal breaker if we hadn't been together very long, but for a long term boyfriend, I think it's okay.
Deal maker ❤ I don't want half-arsed relationships, if I was with someone I'd want it to be the real deal, so it'd be awesome to know that he sees me as marriage material and is serious about what we have.