Welcome to cycling!

Perhaps riding together is giving you an opportunity to witness some dynamics that probably exist throughout your relationship, maybe in more subtle form. Maybe you can both take a loving look at how the two of you interact. In the meantime, if riding together is stressful, or if he's putting you off, then by all means, ride alone.

I started out always MTBing with my husband; I found that riding alone can be much more rewarding for me. We still ride together sometimes, but it's not the default mode. For MTB, I do try to stick to familiar trails where I anticipate other people being around, just in case something happens.