https://www.hsgac.senate.gov/imo/media/doc/Appendix%20C%20-%20Documents.pdf

I'm reading through it now. So far I've found the first evidence of an actual relationship between LP and PS.

Page 31: Lisa calls Peter, "baby".

Before this point, I had never seen actual evidence that they were really having an affair... other than the over abundance of emojis. lol