Offer to help
When you mention that you’re moving, or putting together some furniture, or looking for a new car, does he jump at the chance to help? Does he often look for ways he can be of service to you? Men don’t do that just for a woman they are trying to sleep with or casually date for a short period of time. They save that type of effort for ones they are serious about.
Clarify missed calls
Did he take hours to call back? Did he completely forget to text back? If you’re just someone he is having temporary fun with, he isn’t concerned about you getting pissed about those things. But if he makes a point of saying, “Hey, sorry for taking so long, I was hung up in etc, etc” or “Oh my god I just realized you sent me a text when I was at work and I completely forgot to answer! I’m so sorry!” then you’re not someone he is willing to let go of easily. (Men know how much delayed call or text-backs upset us).
Ask about “that thing”