It is a very nice picture and his tummy is a tiny bit swollen but not too bad. He is just a fat little betta. If you have been giving him his peas (not all the time) he is not constipated so he is just getting pudgy.
No I am sure that he does not think your finger is food. They are smart enough to know that they cannot eat anything that big. I made the mistake with my first betta of taking a q-tip and cleaning around the tank top and he grabbed it out of my hand he bit it and pulled so hard. I felt terrible because he hurt his mouth and was upset with me. So it is always better to keep smaller things out of the tank.
ok so it won't be bad alright! thanks! hes very respectful and like listens like I had a talk with him about him needing to eat more than peas and hes now eating his pellets. I am also getting him those bloodworms asap too. THanks Miley