Samantha pretty much knows - she's caught you both in the act several times and gets off on you banging other chicks as she is both neither stupid and turned on by your sexcapades. You even literally can choose to share your sexcapades with her by the pool and she shows that she can disipher who is the girls on question for a lot of the cases. She is happy to share you with the cousin too so im not expecting fireworks from HER.
Melissa though? hoo boy has she shown possessiveness traits before with Naomi. Could be a bit of reaction there, likewise with Aubrey when she finds out your with her daughter (she not only has been fucking you because of circumstance she is also shown to not be above putting you in your place). I think your getting at least a black eye from her lol.