A 3rd party payment is a deposit made from a payment method that is not in the same name as the owner of the eToro account.
As stated in our Terms & Conditions, the owner of the trading account must be the owner of the funds. Therefore, you are unable to make a deposit using someone else's payment method.
However, if you wish to use a method of payment belonging to your spouse, we can set up a 'Joint Account' for you. This means that both parties will be allowed to deposit or withdraw funds but only the owner of the trading account would be able to carry out trades.
If you wish to set up a joint account, please contact customer service.