Stop allowing loneliness to guide poor decision-making! Stop agreeing to less than what you deserve! Claim someone who is ACTIVELY claiming you!
If he's not exclusive with you, he CAN have options...but if you're exclusive, it means YOU are the only option. Always be assessing whether someone is best for your needs.
If he is consistently comfortable with never having his own, chances are you are not the only one he is taking from and you are training him to never spend wisely nor save to keep his own. Do not ever convince yourself that depleting your resources equates to showing loyalty. It's the oldest form of male manipulation in the book! Men are natural hunters and they always find a way so don't make excuses for capable men.