depends on your plan and resources.
Do you have the income to rent two homes and buy a new one.
Remember most lenders will want to see two years of rental history and perhaps even then only give you 75% of the rent as a reduction in debt to income. So if your income is high enough to pay all the mortgages and you really want to be an investor, this might be the way to go.
If you each have separate homes and want to buy a new one together, I'd most likely suggest selling both and buying the new one.
Anyway if you would like to sit down and discuss all the options, I would be happy to do that with you.