Mary blinked when she saw Lucifer's cheeks growing more pink, and she cupped them with her palms, kissing him gently and shifting her hips pointedly to let him know that she shared his arousal. It seemed silly for either of them to be embarrassed - even though they were, unavoidably so.
Normally, Mary would've worried about what would happen the next day. The aftermath. But Mary didn't care anymore, she just wanted to be with him, at least once. See if her subconscious fantasies were as good as the reality.