Me and my ex husband got in trouble together and got divorced after getting out of prison now want to get married again. Can you get in trouble with your probation officer if you do it without them knowing it

Yes serious trouble.

You can not even associate with another person on probation officer. If they are a co-defendant of the previous crime, just being with them, talking to them, is a serious violation.

You can not talk to them, see them, or be in the same house with them, without permission from your PO.

If the PO finds out, they can revoke the probation and send you before a judge, who may just order you not to see the other again, till off probation. Or they most likely will send you back to prison.

Anything you (OR him) don't reveal to your PO(s) is subject to violation and review, and revocation of parole. Especially marriage to another felon, which is a major violation in itself, ex spouse or NOT. You are asking for BIG trouble by even talking to him. I am sure your probation terms prohibit any contact with felons.