The specific "Mom and Son" themes you mentioned are not part of the official MasterClass catalog. Reviews for sites using similar names often warn of the following:
"I write these stories not to glorify the romance, but to warn against it. On Masticlass.com, I show the mother losing friends, losing her job, losing her sanity. If one reader sees her own possessive love for her son in my villain and seeks help, I’ve done more good than a hundred healthy family dramas." Masticlass.com Indian Mom And Son Sex