How Do I Keep My Wife Satisfied When My Libido Took A Hike Due To Pregnancy?

Dear Thalia,

I'm expecting a child in a few months, and I have lost all desire for sex.

My wife has had two children and i know that when she was pregnant, she was insatiable and constantly in the mood. I feel bad for rejecting her advances, but i just don't want sex! I've talked to her about it and she always says "It's fine." but i think she is just trying to make me feel better.

How do I make her realize that i still want her without becoming a tease?

Sincerely,

Expecting