In a past life, you two had a trying relationship. You may have been diametrically opposed, like jailer and jailed, with your lover being the one kept in prison and you being their jailer. Yikes!
In some way, you had a relationship in which they wanted, needed to speak out, and you silenced them and penalized them for their opinions. That dynamic rears its head again in this life. Especially if your relationship is a long-term one, you start to notice that your lover is nervous about expressing themselves fully. It might be that they're afraid of being interrupted or misunderstood, or it might actually be that you ridicule their opinions or get angry when they say what they really think. They might start to feel like speaking up or standing up for themselves is just pointless -- it doesn't work, they might think, and it just causes trouble. But they shouldn't give in to mental pressures like that, and you should try your hardest to treat them well, with respect. If they find that it's too hard to express themselves, after all, you might lose them when they decide that the relationship isn't worth the sacrifice, or the stress. After all, the best romantic relationships make us feel expansive, as if we can be more truly ourselves than ever before. You should try to stop yourself before you damage the relationship. Each of you has a right to your own opinion.