1. The wife.
aka Laura.
2. The girl who he picks up at the hardware store and then fucks at her house.
aka Corinne.
3. The big-titted girl who gives him her number, who then comes over for a threesome with husband and wife at the end of this installment.
4. The girl who blows him in the park.
The one who gave him her number and blew him in the park is Ellen, who is also the one he is fucking at the start of #3. Corinne came over for the threesome.
5. The girl they are calling up on the phone at the end of this installment; no idea who she is.
Diana. She's new.