That sound 'messy'.
And, of course, the "System" will NOT allow you to "Merge" / "Combine" them.
The circumstances/situation can most likely be addressed/fixed.
But, it is always best to examine the circumstances/situation, before giving any advice.
If you are willing, you can provide the 'FamilySearch Person Identifiers' (PIDs).
That said ...
I do not advocate doing so, if you would prefer not - the choice is yours.
You can also reach out through a (Private) 'Message' through "User Messaging" in this Forum.
I will sent you such a 'Message', where you can respond, in private, if you so prefer.
Otherwise, just respond with the PIDs in post of yours - others can certainly help.
Before you try to merge them, you first need to remove him as being his father. Copy the ID number to use in merging. You should than be able to merge the two. Just be careful you are merging the same person.
Hope this helps,
thank you both for quick reply!