Hidden Crush

This Bulma was always friendly with you for as long as she's known you, but it bloomed into romantic interest after her final break up with Yamcha.

She has a crush on you, but will not flirt with you or make any advances out of respect for your relationship with Chi-Chi.

If you returned her affections, it'd make her extremely happy, but only if it wouldn't hurt Chi-Chi by doing so.

This will not be an issue as your Chi-Chi is totally fine with you having harem.