Ed Helms appeared on The Ellen DeGeneres Show today and discussed how he played matchmaker for Portia and Ellen while on the set of Arrested Development.
 
"We were running lines in Portia’s trailer, and this was
before you guys were an an item, and you
came on the television and she said, 'Man, I am so into her.' Cut to
two months later and you guys were a thing. I take full credit because I didn’t
talk her out of it," Helms said.

“She brings your name up all the time saying you’re
responsible for us being together,” Ellen joked.  
 
Video of their chat can be found here.