As you can see all the milfs in the story except for Layla's mother promiscuous - were sluts and unfortunately still are. If for instance Erynn had not been so loose with her virginity Ethan would never have had the blackmail material / which is still debatable if it is worthy of blackmail in the first place.
Every where you look someone is related to the othere because of the loose attitude Melissa, the mom etc... had
Erynn's far from a slut. She held onto her virginity until around prom and was willing to go all the way with someone she actually liked (Zane). She had no way of knowing Ethan was going to do what he did and it could have happened to anyone at any point in their sexual history.
The logic jumps some people make on this site...
John fucked Melissa...gets Erynn. It's a one night stand and they don't reconnect (until the latest ep).
John meets another woman and has Iris. Sounds like John's the "slut" here.
Melissa just has Erynn and her "relationship" with Emily can't produce children so it's a moot point.
Emily has MC, no other kids. Sure she was promiscuous in college but either she was lucky in pregnancy or practiced safe sex with condoms, etc since MC is her only child.
Haley has Nikki and Cara from her relationship with Mike. Andres didn't have any kids with her and he's definitely the "slut" here.
Layla and Alexis are from Adrianna and Santiago so not sure who is "slutting" there.
Elena...nope.
Tori...sure she gets around.
Sienna...nope.
Lakelyn...maybe? All we know is MC fucked her (if you made that choice).