Thanks to the summoning contract demons cannot betray the summoner. Well, as long as it is reasonable. Any request beyond the original contract annuls it. Such an act testifies that the parties involved are not satisfied with each other.
If one offers a little energy in the process it might tried to kill the summoner. but that kind of thing can be fixed with a proper contract. In any case, slowly summoning a demon is a good idea. As a result, the demon shows due respect.