So on the one hand I ruin a delicious cake and give if not pleasure then hopefully just go with boredom to someone else (I have my own penis but much like I also have my own back but find myself terrible at back rubs I am not sure mere ownership conveys ability, not to mention I am not sure how such things play out when one is as heavily bearded as me). If it was a pie I was potentially ruining then that is a different matter as ruining pie is considered very bad form around here.
When you say sit on a dick does this mean the standard implication of an erect penis going up my ringpiece or am I just sitting on a flaccid one in this scenario? For the former I do rather prefer to keep my colon a one way street so I can not imagine it would be all that pleasurable for me, even if I have cake. For the latter then cake and that I just have to remember to not put my full weight onto it makes it no contest, worst case there I get crabs/lice and those are treated easily enough.