Playful or lighthearted teasing:
* Flirt
* Kid
* Jib
* Rag
* Banter
* Pick on
* Rib
* Taunt (slightly more aggressive)
More serious or malicious teasing:
* Bait
* Goad
* Provoke
* Harass
* Bullying (most severe)
Other options:
* Mock
* Deride
* Ridicule
* Taunt
* Provoke
The best synonym for "tease" will depend on the specific situation. For example, "flirt" might be appropriate if the teasing is playful and romantic, while "harass" would be more fitting if the teasing is aggressive and unwelcome.
It's also important to be aware of the potential impact of your words. Even playful teasing can sometimes be hurtful, so it's always best to be mindful of how your words might be received.