The 'Girls' creator claims the 'Work' hitmaker is her ''greatest passion'' in life and she has an almost religious devotion to the Bajan beauty.
She said: ''She is my greatest passion in life. The way I feel about Rihanna is like the way some people, straight-up, feel about Jesus.''
The 30-year-old actress - who suffers from endometriosis, a condition where small pieces of the womb lining are found outside the womb - admitted she and partner Jack Antonoff are hoping to start a family once she has enjoyed a long period of good health and their career commitments don't get in the way.
She told Stella magazine: ''We would love to have children. We just need to make sure we are doing it at a time where it's not like, 'Congratulations on your baby', and he's like, 'I'm going to Australia for seven months'.
''Pregnancy is a huge physical change, and I have had such a raw experience with my body in my 20s that nothing could make me happier than just having a year of dancing around in my new, healthy body.''
Though Lena and her 32-year-old musician partner are very happy together, she is pleased they don't feel any ''pressure'' to get married.
She said: ''It's not that I am against marriage in any way, but I do like the fact that we have placed zero pressure on ourselves about it.''
And the actress insisted she isn't worried about getting older - just not ''developing'' as a person.
She said: ''I have such youthful parents, who are still so engaged with the work that they make, so I never see ageing as scary.
''What stresses me out is not getting older; it's the idea of not developing, of being stuck.''
His new album Underneath It All is out now.
This overlong comedy is so episodic that watching it is exactly like sitting through five...