I ask this question because unless your marriage is completely and irretrievably broken, at some point you must have a pang of guilt.
My own pang of guilt came literally after my first exaltant moan while coming inside my lover. After all my frustrations with my other half I just wished it was her in front of me.
I've now resolved that the time to stop would be either when I got bored or when those pangs of guilt became a constant companion. After all I don't want to hurt my other half.
2 years ago