Not sure I understand Lauren's position here. She shouldn't have to worry about being 'caught' sleeping with anyone, let alone Peter finding out.
Just seems strange somehow, but I can't really put my finger on why it feels that way. Gotta wonder what she expected Peter to do, and why he'd do it.
@ Kit T.
I think it's a modesty thing or the fact that she's really close friends with Melanie, so her sleeping with Andy so soon after the reveal is probably going to reflect poorly for their relationship.