Mother or Lover?

How old are you?

Do you mean to tell me with all the women in the world available, you want to spend time with your MOTHER sitting on the couch?

That is quite extraordinary if she raised you from birth to adolescence, uninterrupted. The flip side is more explainable:

Over the course of years of living together, even married couples can acquire pseudo-consanguineous feelings about each other which may cause loss of attraction and diminish their sex life. Similar is at work in the usual repulsion that literal genetically-related family members have for each other, which deters incest. However, if a brother and sister, parent and offspring, are separated from each other early on or rarely encountered each other in the past, then it's not remarkable for them to feel some degree of attraction when finally meeting for prolonged periods or residing together for the first time.

Consciously, those involved know they that are related, but the other psychosomatic systems have not been conditioned by time to register the "newcomer" as anything but another potential sex partner, if qualifying for even relaxed versions of their supposed "standards". Combine the latter desire with the emotional feelings conventionally experienced in regard to a sibling or parent, and the combination can be overwhelming for a few of the less disciplined individuals who get caught up in such GSA scenarios.

Since there are countless fabricated accounts of both incest feelings and incest acts dropped and strewn about over internet forums, along with the real ones, I'll leave any advice for your particular situation (which seems to differ from the above cases) to other contributors.