Humble Bundle doesn't require PayPal password when paying by PayPal

[yarda2k]

Hi,

when PayPal is selected in the Humble Bundle as the paying method, the PayPal doesn't ask for the password.  In the Humble Bundle account settings, Payment Information, I don't have PayPal in the saved payments. And in the PayPal I do not have Humble Bundle in the approved payments, so why it behaves this way? Humble Bundle helpdesk wasn't helpful. In the past it always asked for the PayPal password. With other merchants it also always asks for the PayPal password. Is there some minimal money limit which doesn't require PayPal (re)authentication? It were all 1 EUR transactions.

I gave this question the security label because I think this can be a security problem (e.g. anybody with access to my computer can make the payment without authentication).

[yarda2k]

I paid 9 EUR and it's still the same - no password is requested. On the top of the page is written "Hello Jaroslav. It's not you? Login". If I click login it asks for the password. If I click pay, it proceeds without asking for the password. Is there a way how to disable this behavior? Without explicit clearing of the browser cookies upon exit, etc.