But there are other factors involved. Say, for example, if you're really into pleasing your partner, and she loves anal while using a dildo on herself (which is quite a lot of fun. It's the closest thing she'll get to being DP'd without another dude there, and you can feel the dildo vibrating through the vaginal walls which also heightens your own stimulation to a degree). Suddenly it's about the mental stimulation as well as the physical.
Stick or dump?