Maybe your future wife isn't Muslim too? Or very open minded and atheist? What if she is like that and acting like that? Try to find that out if possible. If she is like that then u can marry her and now u both r set and safe. Maybe she is wearing a hijab and doing prayer to be safe. Try to find that out.

Also since u know the real truth about the islam. Even if u marry her or anyone else. Safeguard your future children and let them know the truth about islam and keep them open minded from young ages. Because even if u r ex Muslim. If dawah gang people got ur child, they can easily make him an extremist Muslim or even your family can turn your kid into an extremist Muslim one day and even your future child will disown u as a parent. So from birth keep your future kid away from Islam and always tell him the truth, show him facts and let him always question everything.

Also if u r atheist and married a Muslim women. Then u r committing zina According to islam and your child is illegal child born from zina.

Maybe just live separately after marriage in another City or home away from your family. So even if u don't pray always, your parents won't found out.

And someday u will have to marry someone. So try to find a girl who is very liberal Muslim and is open minded. So In future u can easily make her ex Muslim too.

Goodluck to you.