I'm interested in the reverse opinion here.
I'm a SF, a very disengaged SF. I see several posts on this forum that I can relate to. SD 5 lives with us full time. I can count the number of words that are exchanged on my hands. I am cordial to SD, but do not do her laundry, clean her messes, handle discipline, go on outings, engage in activities. DW is mostly OK with this because I take care of DS1. At the beginning of our relationship, I made my position clear that I was not the father, and I'd most I'd be a fun Uncle, due to the boundaries that were set as far as parenting and discipline by DW. Then we got married, and some fights ensue because of it - nothing that I can't handle - yet. SD is in the process of starting visitation with her BF, asks why I pay so much attention to DS. It doesn't really phase me, I'm totally disengaged. I'm a good husband, and a GREAT father to my child. DW is still having trouble adjusting to having a 2nd parent taking over a child when it comes to my DS.
Thoughts, when it's coming from the opposite gender?