There are 2 kinds of limits in BDSM play, soft limits and hard limits. Soft limits can be pushed, they are things that you’re not sure about but you’re happy to try as long as it stops straight away if you aren’t happy. Hard limits shouldn’t ever be pushed. Ever.
Sometimes limits change. As you grow and evolve as a sub, you may find you enjoy things you didn’t think you would before. But it’s always your choice to downgrade a hard limit to a soft one.
D/s play does often push limits by its nature. If you feel safe with your Dom/me, then letting him push your limits is a good thing. If you don’t feel safe or you feel it’s not something you’re comfortable with doing then don’t do it. The decision is always yours.
A good Dominant will always respect your decisions and only push those limits you allow them to.