I hope that your boyfriend has been to his physcian about his blood pressure since you posted this. If it has been 8 hours or more since he has eaten, his blood sugar should be in the 70-99 range. Even if it is postprandial (after a meal), it should not be above 145. The American Diabetes Association considers a reading of 126 or higher fasting glucose on 2 or more occasions, and/or a 2 hour oral glucose tolerance test (OGTT) is 200 or higher and/or he is experiencing symptoms of diabetes (excessive hunger, excessive thirst, excessive urination, fatigue, tingling or numbness in the hands and feet, blurred vision, or unexplained weight loss). I don't want to scare you, but with a glucose level in the 300s he is potentially at risk for a very, very serious condition called diabetic ketoacidosis (dka), in which his sugar is so high and his insulin levels are so low that essentially his body starts burning fatty acids because it can't take glucose into the cells, causing ketones to be released into the blood and resulting in a dangerously low pH (dangerously acidic blood). If you notice an acetone or fruity odor on his breath or labored breathing (Kussmaul respiration because the bicarbonate anion exchange that is supposed to maintain blood pH within a narrow range can't keep up with the very acidic pH of the blood) get him to a doctor, stat. If he hasn't had one already, he needs to get his glucose tested by a physician, probably both fasting and with an OGTT. Also, it is probably a good idea for him to get his HbA1c tested. HbA1c is glycated hemoglobin and is expressed as a percentage that can be approximated to an average glucose level in the blood. It measures average glucose concentration in the blood over time (usually about the past 3 months). I hope that he can get his blood sugar under control if he hasn't already, because both 317 and 220 are way, way too high for a healthy individual. And if yours was random and not fasting, keep up the good work!
Source: biology major with emphasis/interest in endocrinology, have worked with doctors in 2 different clinics on diabetes prevention, education, and management.