Yeah they are! :D But every time it's making my head more curious and a "WTF" moment because I feel like I'm naive or something.
Ah, one of the great mysteries of the universe, this topic has been explored by hundreds of fanfiction writers everywhere. The coming together of Bulma and Vegeta is never actually shown in the Anime or Manga; it is left up to the viewer's imagination. All that is known is that sometime in the three years before the androids attack, they get together long enough to conceive Trunks. Mirai Trunks tells Goku that Bulma and Yaumcha broke up and out of passion and loneliness Bulma and Vegeta got together
the episodes where bulma and vegeta were the focus are always my favourite (bec they are my OTP in DB lol) I think they want us to read between the lines and bgetween episodes.
*Trunks time travel saga - their relationship here were revealed bit by bit. Keep in mind that future trunks' world is a different world from the current one. It is a tragedy that he doesn't want to happen.
Even if vegeta is not showy, he does care for bulma. Bulma has long got over yamcha at the time. They have broken up because yamcha is a womanizer. They were an item in their early teenage years. It's around the time that goku is still a small snivelling brat and has yet to marry chichi.
At this time, bulma does not travel together that much with goku anymore but she got into helping her father create technology. Homeless and reformed vegeta lived with them because of the facilities bulma's dad offered. He was taken care of by bulma. This is the time they started developing feelings since they frequently see each other. It became obvious in an episode (it's my fave) when bulma got hurt and he got angry for her which shows how they came to care for each other. At this time they got together but as I remember they never get to marry.
I've also wondered this. These two are one of my favorite couples too! xD Vegeta can be such a butthead, lol, but he's like one of those people who shows he cares through his actions, so whenever there are episodes where he does something that often people take for granted for their spouse, I'm just like awwwww, that's so un-Vegeta-like but he's doing it bc he loves Bulma and the two are adorable. :) Bulma is also awesome bc she doesn't let Vegeta push her around (and he tries); she stands her own ground, and I love how they made her a strong and smart female character. lol, sorry I couldn't answer your question; I just wanted to gush.
Got a question that I've been wanting to know... HOW THE HECK DID BULMA AND VEGETA GOT TOGETHER?! Any chapter that told about their love story?