Helppppp

I was looking for a manga Ive read ling time ago in here, it was kind of an incest, there are a pair of a twin living together, an alpha and an omega and they hired like a house keeper which is an omega and the house keeper accidentally saw that twins are having.... you know and he found out that the twins were a pair and they had... kind of threesome but the omega twin got lonely that his twin would leave him because in this story an alpha can mark another omega... onegai please helpppp