Sperm and steak (Bit suggestive)

I text my wife while she was at work today "sperm has as much protein as steak"

"Wow,really, ill have to try some after work " she replied.

5.15pm I heard her car pull up. I stripped naked and lay on sofa ready.

She walked through the door and pointing to the bag in her hand she said

Spoiler:

"I got the steak"